Intra-atrial implants to directionally shunt blood

ABSTRACT

Several unique intracardiac pressure vents, placement catheters, methods of placement and methods of treating heart failure are presented. The intracardiac pressure vents presented allow sufficient flow from the left atrium to the right atrium to relieve elevated left atrial pressure and resulting patient symptoms but also limit the amount of flow from the right atrium to the left atrium to minimize the potential for thrombus or other embolic material from entering the arterial circulation.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.12/719,843, filed Mar. 8, 2010, now U.S. Pat. No. 8,157,860, whichclaims the benefit of U.S. Provisional Patent Application No.61/240,085, filed Sep. 4, 2009. The present application incorporates byreference in their entirety the prior patent applications listed above.The present application also incorporates by reference in their entiretyPCT/AU2007/001704 and Australian Patent Application No. AU 2006906202.

FIELD OF THE INVENTION

The present invention relates generally to devices and methods fortreating heart failure. In particular, the invention relates tointeratrial pressure vents, shunts and the like, which reduce elevatedpressure on one side of the heart thus mitigating the symptoms thatresult, as well as placement devices, systems, and methods therefore.

BACKGROUND OF THE INVENTION

Heart failure is a common and potentially lethal condition affectinghumans, with sub-optimal clinical outcomes often resulting in symptoms,morbidity and/or mortality, despite maximal medical treatment. Inparticular, “diastolic heart failure” refers to the clinical syndrome ofheart failure occurring in the context of preserved left ventricularsystolic function (ejection fraction) and in the absence of majorvalvular disease. This condition is characterized by a stiff leftventricle with decreased compliance and impaired relaxation, which leadsto increased end-diastolic pressure. Approximately one third of patientswith heart failure have diastolic heart failure and there are very few,if any, proven effective treatments.

Symptoms of diastolic heart failure are due, at least in a large part,to an elevation in pressure in the left atrium. In addition to diastolicheart failure, a number of other medical conditions, including systolicdysfunction of the left ventricle and valve disease, can lead toelevated pressures in the left atrium. Increased left atrial pressureoften causes acute or chronic breathlessness amongst other problems. Inaddition, a variety of heart conditions can lead to “right heartfailure”, which can result in enlargement of the liver (hepatomegaly),fluid accumulation in the abdomen (ascites) and/or swelling of the lowerlimbs.

Frequently, patients with diastolic heart failure experiencebreathlessness due, in part, to elevated pulmonary venous pressure.These patients often feel worse when supine than when sitting orstanding, implying that small changes in pulmonary venous pressure havea pronounced effect on symptoms.

In the past, strategies have been described for the relief of highpressure in the right atrium, such as the creation of hole(s) in thenative or surgically created septum between the left and right atria.These have been designed for the rare conditions of pulmonaryhypertension or cavopulmonary connections for certain complex congenitalheart diseases.

Accordingly, there exists a need for devices and methods to treat heartfailure particularly diastolic and/or systolic failure of the leftventricle and its consequences.

Furthermore, there also still exists a need for devices to relieve highpressure in the left atrium and which will prevent or minimize thechance of the passage of thrombi, especially from the right atrium tothe left atrium, and the resulting risk of systemic emboli.

SUMMARY OF INVENTION

It is, therefore, a goal of this invention to effect a reduction inpulmonary venous pressure to ease symptoms of diastolic heart failure.It is a further goal of this invention to create a controlled ventbetween the left atrium and right atrium to allow a sufficient amount ofblood to pass from the left atrium to the right atrium but minimizeblood flow from the right atrium to the left atrium.

It is a further goal of this invention to create a controlled vent thatwill respond to pressure differences between the left and right atrium.

It is a further goal of this invention to provide an interatrialpressure venting device that prevents thrombi from entering the leftatrium.

The present invention solves these and other needs by providing aventing device, which in some embodiments comprises a controlled openingor an extended tubular opening, between the left atrium and right atriumthat allows an amount of blood to vent from the left heart to the rightheart, thereby reducing left atrial pressure and the symptoms associatedwith diastolic heart failure.

Several unique intracardiac pressure vents, placement catheters, methodsof placement and methods of treating heart failure are presented. Theintracardiac pressure vents presented allow sufficient flow from theleft atrium to the right atrium to relieve elevated left atrial pressureand resulting patient symptoms but also limit the amount of flow fromthe right atrium to the left atrium to minimize the potential forthrombi or other embolic material from entering the arterialcirculation.

In addition, the intracardiac pressure vents presented solve the problemof controlling flow in one direction but minimizing flow in anotherdirection with very low changes in pressure across the device.

Also, the intracardiac pressure vents presented solve the problem ofreducing calcium deposition, protein deposition and thrombi formation ina low pressure environment.

Furthermore, the intracardiac pressure vents presented solve the problemof damage to the interatrial septum as well as the rest of the leftatrium from excessive pressure against the wall which can cause injuryto the tissue and possibly adverse reaction by the patient orcompromised function to the interatrial pressure vent.

In addition, atrial arrhythmias are frequently seen in patients withheart failure and may, in part, be caused by chronically elevated leftatrial pressure. Therefore, relief of elevated left atrial pressure maylead to reduction of atrial fibrillation.

The present invention provides interatrial pressure vents, placementcatheters, methods for placing a device in the interatrial septum withinthe heart of a patient and methods for treatment of the symptoms ofheart failure, particularly diastolic heart failure.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element; the body assembly comprises a flexible,substantially open mesh adapted for use in a patient. The flow controlelement attaches to at least one point of the body assembly and the flowcontrol element provides greater resistance to flow in one directionthan it does in another direction.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element; the body assembly comprises a flexible,substantially open mesh adapted for use in a patient. The flow controlelement attaches to at least one point of the body assembly and is atleast partially open to flow when there is no pressure differentialacross the flow control element.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element; the body assembly comprises a core segmentand at least one flange segment; the flange segment is integral with, orattached to at least one point adjacent to, an end of the core segment;the flange segment extends radially outward from the center longitudinalaxis of the core segment. The flow control element attaches to at leastone point along the core segment and the flow control element providesgreater resistance to flow in one direction than in the oppositedirection.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element; the body assembly comprises a substantiallycylindrical core segment and at least one flange segment; the flangesegment is integral with, or attached at least to one point adjacent to,an end of the core segment; the flange segment extending radiallyoutward from the center longitudinal axis of the core segment. The flowcontrol element attaches to at least one point along the core segmentand the flow control element provides greater resistance to flow in onedirection than another direction.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element. The body assembly comprises a substantiallycylindrical core segment and at least one flange segment integral with,or attached to at least one end of, the core segment; the flange segmentextending radially outward from the axis of the core segment. The flowcontrol element attaches to at least one point along the core segmentand the flow control element is at least partially open to flow whenthere is no pressure differential across the flow control element.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element. The body assembly comprises a substantiallycylindrical core segment and at least one flange segment integral with,or attached to at least one end of, the core segment and extending awayfrom the axis of the core segment. The flow control element attaches toat least one point along the flange assembly and provides greaterresistance to flow in one direction than the other direction.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element. The body assembly comprises a substantiallycylindrical core segment and at least one flange segment integral with,or attached to at least one end of, the core segment and extending awayfrom the axis of the core segment. The flow control element attaches toat least one point along the flange assembly and is at least partiallyopen to flow when there is no pressure differential across the flowcontrol element.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element. The body assembly comprises a substantiallycylindrical core segment and at least one flange segment integral with,or attached to at least one end of, the core segment and extending awayfrom the axis of the core segment. The flow control element extends atleast partly onto the flange assembly and creates a sealable contact tothe atrial septum and provides greater resistance to flow in onedirection than the other direction.

In embodiments, the interatrial pressure vent comprises a body assemblyand a flow control element. The body assembly comprises a substantiallycylindrical core segment and at least one flange segment integral with,or attached to, at least one end of the core segment and extends awayfrom the axis of the core segment. The flow control element attaches tothe flange assembly and creates a sealable connection to the atrialseptum and is at least partially open to flow when there is no pressuredifferential across the flow control element.

In embodiments, the interatrial pressure vent comprises a body assemblywith a first end and a second end and a flow control element; the bodyassembly comprises a core segment including at least one flange segmentintegral with, or attached to, at least one point adjacent to the firstend of the core segment and at least one other flange segment integralwith, or attached to, at least one point adjacent to the second end ofthe core segment; the flange segments extending radially outward fromthe center longitudinal axis of the core segment and the flange segmentsoriented so they do not oppose each other when deployed. The flowcontrol element attaches to at least one point along the core segmentand the flow control element provides greater resistance to flow in onedirection than it does in another direction.

In embodiments, the interatrial pressure vent comprises a body assemblywith a first end and a second end and a flow control element; the bodyassembly comprises a core segment including at least one flange segmentintegral with, or attached to, at least one point adjacent to the firstend of the core segment and at least one other flange segment integralwith, or attached to, at least one point adjacent to the second end ofthe core segment; the flange segments extending radially outward fromthe center longitudinal axis of the core segment and the flange segmentsoriented so they do not oppose each other when deployed. The flowcontrol element attaches to at least one point along the core segmentand the flow control element is at least partially open to flow whenthere is no pressure differential across the flow control element.

In embodiments, the interatrial pressure vent comprises a body assemblywith a first end and a second end and a flow control element comprisedof at least one leaflet; the body assembly comprises a substantiallycylindrical core segment and a number of flange segments integral with,or attached to, at least one point on each side of the body segment andextending radially outward from the center longitudinal axis of the coresegment; the number of flange segments on either side of the coresegment being a whole multiple of the number of leaflets.

In embodiments, the interatrial pressure vent comprises a body assemblywith a first end and a second end and a flow control element comprisedof at least one leaflet; the body assembly comprises a substantiallycylindrical core segment and a number of flange segments integral with,or attached to, at least one point on each side of the body segment andextending radially outward from the center longitudinal axis of the coresegment; the number of flange segments being a whole multiple of thenumber of leaflets. The flow control element attaches to at least onepoint of the body assembly and the flow control element provides greaterresistance to flow in one direction than another direction.

In embodiments, the interatrial pressure vent comprises a body assemblywith a first end and a second end and a flow control element comprisedof at least one leaflet; the body assembly comprises a substantiallycylindrical core segment and a number of flange segments integral with,or attached to, at least one point on each side of the body segment andextending radially outward from the center longitudinal axis of the coresegment; the number of flange segments being some multiple of the numberof leaflets. The flow control element attaches to at least one point ofthe body assembly and is at least partially open to flow when there isno pressure differential across the flow control element.

In embodiments, an implant system comprises an interatrial pressure ventand placement catheter for treating heart failure. The implant system iscomprised of a body assembly and a flow control element. The bodyassembly is comprised of a substantially cylindrical core segment and atleast one flange segment integral with, or attached to, at least one endof the core segment and extending radially away from the core segment.The flow control element is attached to at least one point along thecore segment and provides greater resistance to flow in one directionthan the other direction. The placement catheter is comprised of aninner shaft and an outer shaft. The inner shaft comprises an elongatetube and a handle component. The inner shaft also contains at least onelumen that extends along at least part of the length of the inner shaft.The outer shaft comprises an elongate hollow tube or sheath and adifferent handle component that slideably interfaces with the firsthandle component.

In embodiments, an implant system comprises and interatrial pressurevent and placement catheter for treating heart failure. The implantsystem is comprised of a body assembly and a flow control element. Thebody assembly is comprised of a substantially cylindrical core segmentand at least one flange segment integral with, or attached to, at leastone end of the body assembly and extending radially away from the bodysegment. The flow control element is attached to at least one pointalong a flange and provides greater resistance to flow in one directionthan the other direction. The placement catheter is comprised of aninner shaft and an outer shaft. The inner shaft comprises an elongatetube and a handle component. The inner shaft also contains at least onelumen that extends along at least part of the length of the inner shaft.The outer shaft comprises an elongate hollow tube (or sheath) and adifferent handle component that slideably interfaces with the firsthandle component.

In embodiments, an implant system comprises and interatrial pressurevent and placement catheter for treating heart failure. The implantsystem is comprised of a body assembly and a flow control element. Thebody assembly is comprised of a substantially cylindrical core segmentand at least one flange segment integral with, or attached to, at leastone end of the body assembly and extending radially away from the bodysegment. The flow control element is attached to at least one pointalong a flange and provides greater resistance to flow in one directionthan the other direction. The placement catheter is comprised of aninner shaft and an outer shaft. The inner shaft comprises an elongatetube with at least one flange or circumferential groove formed in theouter diameter and a handle component. The inner shaft also contains atleast one lumen that extends along at least part of the length of theinner shaft. The outer shaft comprises an elongate hollow tube (orsheath) and a different handle component that slideably interfaces withthe first handle component.

In other embodiments, the invention comprises a device for treating aheart condition in a patient comprising a body element having a coresegment defining a passage, a first annular flange comprising aplurality of flange segments, and a second annular flange comprising aplurality of flange segments. In embodiments, at least a portion of oneof the flange segments is either more or less flexible than theremaining portion of the flange segment or other portions of the bodyelement, including but not limited to the cylindrical core segment.

In other embodiments, the device comprise a third or intermediateannular flange for better adherence to the septal wall.

In other embodiments, the device comprises a flow control elementconfigured to aim the flow of blood in a desired direction.

In other embodiments, the invention is configured to be more easilyretrieved during deployment. Such embodiments can include among otherelements a at least one extended flange segment in one of the annularflanges that is able to be retained within a placement catheter when theother portions of the device are deployed.

In embodiments, the method of placing the interatrial pressure vent intoposition may comprise a sequence of steps to locate and gain access to avascular channel leading to the heart, placing an introducer cathetervia this channel into one of the atriums of the heart, locating theinteratrial septum between the left and right atriums, creating anopening in the interatrial septum, advancing a placement cathetercontaining an interatrial pressure vent into one of the atriums and thenthrough the opening created in the interatrial septum between the rightand left atriums, and then controllably deploying the interatrialpressure vent so it is securably connected to the interatrial septum.

Deployment of the interatrial pressure vent preferably occurs in aseries of steps comprising first advancing the placement catheterthrough the septal opening, second deploying a first flange, thirdretracting the placement catheter to position the first flange againstthe septal wall, and fourth deploying a second flange on the other sideof the septal wall from the first flange.

In embodiments where the device disclosed herein is implanted into theatrial septum, the introducer catheter may be placed through theinferior vena cava via a femoral vein to the right atrium.

Other pathways are available including placing the introducer catheterthrough the superior vena cava via a jugular vein; through the aorta,via a femoral artery, past the aortic valve and into the left atrium;through the aorta, via a brachial artery, past the aortic valve and intothe left atrium; through the superior vena cava via a basilica vein;through the superior vena cava via a cephalic vein; intraoperatively,through an opening created in the right atrium either for this reason orduring a procedure performed for some other purpose; intraoperativelythrough an opening created in the left atrium either for this reason orduring a procedure performed for some other reason; orvia a guidewirethat is positioned through the interatrial septum and located in thepulmonary artery.

Regarding the placement catheter, in some embodiments the placementcatheter is designed to function as the introducer catheter and theplacement catheter, eliminating the need for a catheter exchange. Whilein other embodiments, the introducer catheter, the placement catheter,or both are constructed to be exchanged over only part of their lengthto avoid the necessity of handling a guidewire that is at least twice aslong as the catheter. Still in other embodiments, the introducercatheter or the placement catheter, or both has a pre-shaped curve toenable orientation of the placement catheter substantially orthogonal tothe septal wall. The catheter may be curved between 30° and 45° awayfrom the catheter axis at a point between 5 and 15 centimeters away fromthe distal end of the placement catheter.

In embodiments of the invention where the inventive device is to beplaced in the atrial septum, an opening in the septum can be performedusing the introducer catheter in a separate procedure from theinteratrial pressure vent placement procedure. Access through theopening can be maintained via a wireguide positioned in the right atriumor the pulmonary artery. The opening can be formed using the placementcatheter via a distal tip segment that is part of the placementcatheter.

The opening may be predilated using a balloon or other dilating deviceeither as part of the procedure described or as a separate procedure.

In another aspect, the opening is formed and dilated as part of asingle, unified procedure with the interatrial pressure vent placementprocedure. This may be accomplished by integrating a balloon or otherdilating component as part of the placement catheter and dilating theopening as part of placing the interatrial pressure vent. For example,this could be accomplished using a balloon that can be folded to achievea small loaded profile and will have a suitable pressure capacity andsuitable durability to dilate the septum opening and the interatrialpressure vent together.

The opening that is formed in the interatrial septum may be formed bypushing a catheter tip through the septum at the location of septumprimum. Because this septum is normally very thin, the distal tip may bepushed directly through without significant force.

In an alternate method, the opening in the interatrial septum can beformed with a cutting tool that is advanced through the introducercatheter or the placement catheter. The tool preferably comprises ablade and a shaft. The blade contains at least two surfaces and oneedge. The edge is sharpened and formed at an angle so that the bladeslices as it is advanced into and through the septum.

In yet another method, the opening in the interatrial septum can beformed with a cutting tool that is advanced through the introducercatheter or the placement catheter. The tool preferably comprises ablade and a shaft. The blade contains at least two surfaces and twoseparate edges that are sharpened at an angle so that the blade slicesas it is advanced into and through the septum and the septum is cutgenerally in an x shaped opening.

In yet another method, the opening in the interatrial septum can beformed with a punching tool that is advanced through the introducercatheter or the placement catheter. The punching tool preferablycomprises a cutting assembly and a shaft. The cutting assemblypreferably comprises a hollow, conical shape with a sharpened edge alongthe base circumference. The cutting assembly is connected at least toone point on the shaft and is generally oriented so the apex of the coneis pointed away from the shaft.

In one method, the cutting assembly can be operated by advancing theconical assembly through the interatrial septum and then pulling it backto form an opening that is generally circular.

In another method, the cutting assembly can be operated by advancing theconical assembly through the interatrial septum and then rotating it asit is pulled pack to create a circular cutting action against theinteratrial septum.

In another embodiment, the cutting tool can be formed of at least onecutting member and one shaft. The cutting member is connected at leastto one point along the shaft and the other end of the cutting member isadjustably positioned so it can lay alongside the shaft or at some angleaway from the shaft. To place the cutting tool, the cutting member isplaced alongside the shaft and then advanced through the septum. Thenthe cutting member would be adjusted to a second position, radiallyfurther away from the shaft than the first position, and the shaft wouldbe positioned so the cutting member exerts lateral stress against theseptum. The cutting member could be designed to slice the septum in thismanner. In another method, the cutting tool could be rotated once theshaft and cutting member were repositioned so the slicing motion wouldcut a generally circular hole through the septum.

In embodiments, the cutting member is round wire.

In another embodiment, the cutting member can be connected to one outputof a power supply, capable of supplying a suitable signal to the cuttingmember, the other output of which is connected to a ground plate placedagainst the patient's skin. An appropriate electric potential can beplaced between the cutting member and ground plate to cause aconcentrated current density near the wire to aid in cutting through theseptum tissue.

In another embodiment, the cutting member is a section of tubing slicedlengthwise and appropriately formed to create a cutting edge. Duringplacement, the cutting member is controllably positioned to lie againstthe shaft as the shaft is advanced through the placement catheter andthrough the opening created in the interatrial septum. Once positioned,the placement catheter is retracted and the shaft is positioned withinthe septum. Once positioned in this manner, the cutting member can becontrollably adjusted to a second position, radially further away fromthe shaft than the first position, and the shaft positioned so thecutting member exerts lateral stress against the septum.

In yet another method, an opening is created in the interatrial septumwhich is smaller than the diameter of the outer surface of the body ofthe interatrial pressure vent according to the present invention suchthat, when the interatrial pressure vent is initially deployed withinthe interatrial septum, there is some compression from the septumagainst the body of the interatrial pressure vent.

Referring now to the placement catheter used to position andcontrollably place the interatrial pressure vent; in one aspect, theplacement catheter consists of an inner member and an outer member.

In embodiments, the outer member is comprised of a tubing member and afirst handle component, the outer shaft is less than about 16 F indiameter and formed of a material suitably smooth and resilient in orderto restrain the stowed interatrial pressure vent and allow smoothstowing and deployment, such as PTFE, FEP, Tefzel, PVDF, HDPE or othersuitable materials.

In embodiments, the inner member is comprised of at least one tubingmember with an inner lumen through at least part of the tubing member,and a second handle component attached to the proximal end, with thesecond handle component slideably attached to the first handlecomponent.

In embodiments, the handle components are interconnected via aninclined, helical lever to enable advancement of the inner memberrelative to the outer member by rotating the outer shaft handle whileholding the inner shaft handle.

In embodiments, the handle components comprise a locking mechanism thatprevents the handle component from moving in relationship to each otherbeyond a certain predetermined length

In embodiments, the handle components contain at least two lockingmechanisms that prevents the handle component from moving inrelationship to each other beyond two different predetermined length

In embodiments, the inner member contains a stiffening element adjacentto the distal area.

In embodiments, a system for treating heart failure in a patientconsists of an interatrial pressure vent and placement device. Theinteratrial pressure vent comprises a body section and a flow controlelement. The body section comprises a core section and at least oneflange segment. The flange segment comprises a midsection adjacent tothe body and an end section that has a greater wall thickness than themidsection. The placement device comprises an inner shaft and an outershaft. The inner shaft comprises an outside diameter and an internallumen extending at least partly toward the proximal end from the distalend. The outer shaft contains an outside diameter and an insidediameter. The inner shaft contains a necked portion or circumferentialgroove along at least part of its length of smaller diameter than atleast a portion of the inner member distal to the necked portion; thespace formed between the outside of the necked portion and the inside ofthe outer shaft being sufficient to contain a folded or otherwisecompressed interatrial pressure vent of the present invention and thespace formed between the outside of the non-necked portion and theinside of the outer shaft being insufficient to contain the interatrialpressure vent.

In embodiments, a system for treating heart failure in a patientconsists of an interatrial pressure vent and placement device. Theinteratrial pressure vent comprises a body section and a flow controlelement. The body section comprises a core section and at least oneflange segment. The flange segment comprises a midsection adjacent tothe body and an end section located radially further away than themidsection and with a larger dimension in the radial direction than themidsection. The placement device comprises an inner shaft and an outershaft. The inner shaft contains an outside diameter and an internallumen extending at least partly toward the proximal end from the distalend. The outer shaft contains an outside diameter and an insidediameter. The inner shaft contains a first necked portion orcircumferential groove comprising a length and a diameter; the diameterof the first necked portion of the inner shaft being smaller than atleast a portion of the inner member distal to the necked portion and theinner shaft also containing a second necked portion, proximal to thefirst necked portion and of a length sufficient for containing endsection of the flange segment and a diameter smaller than the firstnecked portion; the space formed between the outside of the first neckedportion and the inside of the outer shaft being sufficient to containthe folded or otherwise compressed interatrial pressure vent of thepresent invention except for the end section of the flange segment; thespace formed between the outside of the non-necked portion and theinside of the outer shaft being insufficient to contain the interatrialpressure vent and the space formed between the outside of the secondnecked portion and the inside of the outer shaft being sufficient tocontain the end section of the flange segment.

In another aspect, the inner member comprises a first necked portionalong at least part of its length of smaller diameter than at least aportion of the inner member distal to the first necked portion andsecond necked portion, along a second part of its length proximal to thefirst necked portion and smaller than the first necked portion. Thespace between the outside of the necked portion and the inside of theouter sheath.

Referring now to the body assembly of the interatrial pressure vent, inone aspect, the body comprises a core segment and at least one flangesegment.

In embodiments, the body assembly comprises a core segment; a firstflange comprising at least one flange segment at one end of the coresegment; and a second flange comprising at least one flange segment atthe opposite end from the first flange of the core segment.

In embodiments, the body assembly comprises a core segment, comprising aself expanding mesh; a first flange, at one end of the core segment; anda second flange at the opposite end of the core segment from the firstflange.

In embodiments, the body assembly is comprised of a core segment,comprising a balloon expandable mesh; a first flange at one end of thecore segment; and a second flange at the opposite end of the coresegment from the first flange.

In embodiments, the body assembly is comprised of a core segment; afirst flange at one end of the core segment; and a second flange at theopposite end of the core segment from the first flange; each flangeoriented to extend substantially radially outward relative to the centeraxis the flange segment.

In embodiments, the body assembly is comprised of a core segment; afirst flange at one end of the core segment; and a second flange at theopposite end of the core segment from the first flange; each flangeoriented to extend substantially radially outward from the core segment;and at least one flange extending beyond 90° relative to the center axisof the core segment.

In embodiments, the body assembly is comprised of a core segment; afirst flange at one end of the core segment; and a second flange at theopposite end from the first flange of the core segment; each flangeoriented to extend substantially radially outward from the core segment;the first flange formed with a smaller radius of curvature than thesecond flange.

In embodiments the interatrial pressure vent comprises a flow controlelement biased to allow flow from one atrium of a patient to the otheratrium of the patient with lower resistance than in the reversedirection.

In embodiments the interatrial pressure vent comprises a flow controlelement biased that remains at least partially open when there is nopressure differential across the vent.

In embodiments, the interatrial pressure vent comprises an integralfilter to prevent embolic particles larger than about 2 mm from passingbeyond the filter in the direction of flow.

In other embodiments, the interatrial pressure vent comprises a tubularflow element which extends a distance beyond the core segment so as toprevent embolic particles from entering the left atrium.

In embodiments, the interatrial pressure vent comprises at least onemovable flap that responds to pressure changes between the right andleft atrium.

In embodiments, the body assembly may be constructed from preformed wirebraid. The wire braid may be formed from nitinol with amartensite/austenite transition temperature is below 37° C. so itremains in its superelastic, austenitic phase during use. The transitiontemperature is below about 25+/−5° C. The wire should have a diameter ofat least about 0.0035 (about 2 lbs of breaking strength at 200 ksitensile). The wire should have a very smooth surface to reducethrombogenicity or irritation response from the tissue. The surfacefinish may be 63 uin RA or better. This surface may be obtained eitherby mechanical polishing, by electropolishing or a combination. Inembodiments, the surface may be cleaned with detergents, acids and/orsolvents to remove residual oils or contamination and then controllablypassivated to insure minimal corrosion.

In embodiments, the body assembly may be formed from grade 1 titanium.In embodiments, the body may be formed of grade 6 titanium. Inembodiments, the body may be formed of grade 9 titanium. In embodiments,the body may be formed of 316L stainless steel. In embodiments, the bodymay be formed of 416L stainless steel. In embodiments, the body may beformed of nitinol or Elgiloy. In embodiments, the body is formed ofplatinum iridium. In embodiments, the body may be formed of a cobaltchromium alloy. In embodiments, the body may be formed of MP35N. Inembodiments, the body may be formed of Vitalium™. In embodiments, thebody may be formed of Ticonium™. In embodiments, the body may be formedof Stellite™. In embodiments, the body may be formed of tantalum. Inembodiments, the body may be formed of platinum. Materials disclosedwith reference to the body or any component of the device disclosedherein are not meant to be limiting. The skilled artisan will appreciatethat other suitable materials may be used for the body or any othercomponent of the device.

In embodiments, the body assembly is preferably formed from a length ofcylindrical tubing that is precut with slots at specific locations andthen formed in a series of processes to produce a shape suited for thepurpose of containing a flow control element within the interatrialseptum.

As an example, a first process might be to stretch the cylinder toexpand its internal diameter to a uniform target dimension. This can bedone with a balloon or a standard tubing expander consisting of asegmented sleeve and tapered conical inserts that increase the diameterof the sleeve when the cones are advanced toward the center. In orderthat the shape of the stretched tubing be preserved, the cylinder shouldbe annealed while held into this stretched shape by heating it beyond300° to 600° for at least about 20 minutes to allow the internalstresses to be relieved. A second process might be to form one flangeend shape using a similar process as the first process but using a toolshape specially designed for the first flange shape. A third processmight be to form the second flange end shape using a similar process asthe first process but using a tool specially designed for the thirdflange shape. These shapes must be annealed using a similar process asthe first shape, either in separate steps or altogether.

In embodiments, the internal diameter of the finished interatrialpressure vent is larger than about 5 mm to enable adequate venting ofthe left atrium and minimize damage to blood components from excessiveshear stress, but enabling the interatrial pressure vent to stow in aplacement catheter of smaller than about 14 F.

In embodiments, the flow control element opening is at least about 50sq. mm.

In embodiments, the flow control element opening is 50 sq. mm. +−10 sq.mm.

In another embodiment, the cylindrical section is formed with an insidediameter of between 3 and 15 mm.

The internal diameter of the body segment is preferably a constantdimension along the center, longitudinal axis of the interatrialpressure vent and is long enough to isolate the flow control elementfrom deflection or damage as a result of contact with other structuralelements of the heart.

In embodiments, the body segment is formed into a substantially toroidalshape, the inner diameter tapering down and then up again from one sideof the implant to the other.

In embodiments, the length of the body section may be about 4 mm.

In embodiments, the length of the body section may be between about 3 mmand about 40 mm.

In yet other embodiments, the flange segment may comprise at least asingle loop which is oriented to the cylindrical shape by at least about90° relative to the central axis of the cylinder and projected outwardto a distance away from the center axis of greater than the opening inthe atrial septum but at least about 3 mm further than the diameter ofthe inner cylinder.

In embodiments, the flange segment is formed of multiple struts thatextend radially outward, with respect to the center aspect of thecylinder.

In embodiments, the flange struts each comprise a substantiallytriangular shape that is wider adjacent to the body section than at theouter edge of the strut.

In embodiments, the flange struts comprise a substantially triangularshape that is wider adjacent to the body section than at the outer edgeof the strut and contains an integral hole at the outer edge forcontaining a radiopaque marker.

In embodiments, the flange struts comprise a substantially triangularshape that is wider adjacent to the body section than at the outer edgeof the strut and whose outer edge is rounded to reduce trauma againstthe tissue it contacts.

In embodiments, the flange struts are formed from a single beam ofmaterial that project outward from the center longitudinal axis of thebody section.

In embodiments, the flange segment is formed of spiral shaped flangestruts that are coplanar and substantially orthogonal to the centralaxis of the cylinder.

In embodiments, the flange segment is formed of at least one loopingmember that attaches to at least one portion of the body section.

In embodiments, the flange is preferably formed to automatically recoversubstantially to its preformed shape following partial deployment of theinteratrial pressure vent from the placement catheter. In this manner,the interatrial pressure vent will resist being pulled back through theseptal opening.

In embodiments, the flow control element device may be a tissue valve, asynthetic valve or a combination. The flow control element can be formedfrom animal or human tissue, such as bovine pericardial tissue. Theprocedures for obtaining these tissues and preparing them for use asimplanted valve components are well known to those skilled in the art.The flow control element could be a trileaflet valve, or also abileaflet valve, or also a simple flap valve. The flow control elementcould also be a ball and socket valve, a duckbill valve, a butterflyvalve, or any other valve component known to those skilled in the art.

In embodiments, the flow control element can be biased by adding aseparate component that is attached to at least one point along the bodyor flange segment and contacts against at least one point of the flowcontrol element surface at least at some point during its duty cycle.The component can be preformed to controllably affect the flow controlelement behavior. For example, in one embodiment, the flange segment canbe a looped wire formed from nitinol and connected to the body sectionand cantilevered against the surface of the flow control element facingthe left atrium and formed so that the surface of the flow controlelement is biased to be slightly open when the pressure is equal in theleft atrium and right atrium. Biasing can also be accomplished byvarying the stiffness of the material of the valve or componentsthereof.

In embodiments, a flange segment could be formed out of a helicalwinding of nitinol, with a core wire to connect one end of the flangesegment to the other end.

In embodiments, the flow control element can be preshaped to resistmoving against pressure in one direction.

In embodiments, the flow control element could be biased to remain openat a predetermined pressure, or at a neutral pressure.

In embodiments, the interatrial pressure vent consists of a body sectionand a flow control element; the body section comprising a cylindricalcore segment and two flanged end sections; the flow control elementbeing sealably secured to at least three points along the body section;the flanged end sections each comprising at least one flange segmentthat extends radially outward from the body section; the flow controlelement comprising at least one movable element that allows fluidpassage in one direction with lower resistance than another direction.

In embodiments, the body section is elliptical in shape, or cylindriodand designed to offset asymmetric stress created by a linear septalopening.

In embodiments, the formed metal flange segments consist of at least twoflange segments, with at least one on each side of the septum.

In embodiments, the flange segments are positioned so they do not pinchthe septum between them, thereby reducing possible pressure necrosis.

In embodiments, the flange segments are shaped so the wall thicknessperpendicular to the septum is less than the wall thickness parallel tothe septum, thereby increasing flexibility without decreasing strength.

In embodiments, the flange segments are formed so the radius ofcurvature at the end is greater than about 0.03 inches.

In embodiments, there is a radiopaque marker, preferably tantalum orplatinum alloy, formed around, or integral with, the flange segment endto increase radiopacity and increase the area of contact between theflange segment and septum.

In embodiments, the flange on the left atrium side of the septum is bentat a shorter radius of curvature than the right atrium side.

In embodiments, the flange on one side of the interatrial septum isformed to return to greater than a 90° angle relative to the axis of thecenter cylinder.

In embodiments, holes are preformed at a location along the cylindricalsection for suture sites for securing the valving device.

The above summary of the invention is not meant to be exhaustive. Othervariations and embodiments will become apparent from the descriptionand/or accompanying figures disclosed herein and below. The embodimentsdescribed above employ elements of each other and are meant to becombined with each other. For example, embodiments of flow controlelement may be used with differing configurations of the body element,flange, or segment thereof. While certain combinations are disclosed,the invention is not so limited

BRIEF DESCRIPTION OF DRAWINGS

The present invention will become more fully apparent from the followingdescription and appended claims, taken in conjunction with theaccompanying figures. Understanding that these figures merely depictexemplary embodiments of the present invention they are, therefore, notto be considered limiting of its scope. It will be readily appreciatedthat the components of the present invention, as generally described andillustrated in the figures herein, could be arranged and designed in awide variety of different configurations. Nonetheless, the inventionwill be described and explained with additional specificity and detailthrough the use of the accompanying figures in which:

FIG. 1 is a schematic cross-sectional view of a patient's heart with aninteratrial pressure vent of the present invention in situ;

FIG. 2 is an end view of the interatrial pressure vent of FIG. 1 in situas seen along line 2-2 of FIG. 1;

FIG. 2A is a end-on close up view of a flange segment of an embodimentof the present invention;

FIG. 2B is an enlarged side cross-sectional view of an embodiment of theinvention to illustrate variations in flexibility in a flange;

FIG. 3 is a cross-sectional side view taken along line 3-3 of FIG. 2;

FIG. 4 is perspective view of the body assembly of the interatrialpressure vent by itself;

FIG. 5 is a right side view of the body assembly of FIG. 4;

FIG. 6 is a distal end view of the body assembly of FIG. 4;

FIG. 7 is an enlarged fragmentary cross-sectional view taken along line7-7 of FIG. 6;

FIGS. 7A through 7C are a side elevational views of embodiments of thedevice in the stowed position;

FIG. 8 is a side elevational view of the interatrial pressure vent ofFIG. 1 in a collapsed configuration prior to loading in a placementcatheter;

FIG. 9 is a side view of the distal end of a placement catheter in itsopen position;

FIG. 10 is a side view of the distal end of a placement catheter in itsopen position and with an interatrial pressure vent in its stowedconfiguration and in position over the inner shaft of the catheter;

FIG. 11 is a side view of the distal end of a placement catheter in aclosed configuration with an interatrial pressure vent in its stowedconfiguration loaded onto the placement catheter;

FIG. 11A is a side view of another embodiment of a placement catheterwith an interatrial pressure vent stowed therein;

FIG. 12 is an exploded perspective view of the proximal and distal endsof a placement catheter;

FIG. 13 is a cutaway view of a heart of a patient and the distal end ofa placement catheter in position across the interatrial septum;

FIG. 14 is a schematic cross sectional side view of the proximal anddistal end of a placement catheter in a closed position and positionedacross the interatrial septum of the heart of a patient;

FIG. 15 is a view similar to FIG. 14 but showing the distal end of theplacement catheter in a partially open position and the distal flangesegments of the interatrial pressure vent deployed;

FIG. 16 is a view similar to FIG. 15 but showing the distal flangesegments of the interatrial pressure vent in position against the wallof the interatrial septum;

FIG. 17 is an enlarged cross-sectional detail view of the distal end ofthe placement catheter of FIG. 16 but showing the distal flange segmentsof the interatrial pressure vent being retracted from the interatrialseptum as if it were determined to be in an undesirable position byimaging the radiopaque markers and going to be redeployed;

FIG. 18 is a view similar to FIG. 16 but showing further deployment ofthe interatrial pressure vent by releasing the proximal flange segmentsif imaging determines a correct positioning of the distal flangesegments;

FIG. 19 is an enlarged cross-sectional detail view of the placement;catheter of FIG. 18 but showing the interatrial pressure vent fullyreleased in position and the placement catheter being removed;

FIG. 19A is schematic depiction of another embodiment of a placementcatheter system and interatrial pressure device along with thedeployment process therefor;

FIG. 19B is schematic depiction of another embodiment of a placementcatheter system and deployment process therefor;

FIG. 20 is a side elevational view of an alternate embodiment of aninteratrial pressure vent body with slanted flange segment ends;

FIG. 21 is a side elevational view of an alternate embodiment of aninteratrial pressure vent body with staggered flange segment ends;

FIG. 22 is a perspective view of an alternate embodiment of aninteratrial pressure vent body with an integrated retrieval means andthrombus clot strainer;

FIG. 23 is a right side view of the body assembly of FIG. 22;

FIG. 24 is an end view of an alternate embodiment of interatrialpressure vent;

FIG. 25 is a cross-sectional side view taken along line 25-25 of FIG.24;

FIG. 26 shows and alternate embodiment wherein the core segment 106 isovular rather than circular and thus the core segment is a cylindroid orelliptic cylinder rather than a simple cylinder;

FIG. 27 is schematic depiction of another embodiment of a placementcatheter system and interatrial pressure device along with thedeployment process therefor;

FIG. 27A is a side elevational view of the embodiment described inconnection with FIG. 27 in the stowed position;

FIGS. 28A through 28C depict other embodiments of the device that directthe flow of blood in a desired direction;

FIG. 29 is an end-on view from the RA side of embodiments of exitprofiles of the flow control element; and

FIG. 30 is a side view of an embodiment of the device having a tube-likeextension into the RA side of the heart.

DETAILED DESCRIPTION OF INVENTION

Certain specific details are set forth in the following description andFigures to provide an understanding of various embodiments of theinvention. Those of ordinary skill in the relevant art will understandthat they can practice other embodiments of the invention without one ormore of the details described below. Finally, while various processesare described with reference to steps and sequences in the followingdisclosure the steps and sequences of steps should not be taken asrequired to practice all embodiments of invention.

As used herein, the terms “subject” and “patient” refer to any animal,such as a mammal like livestock, pets, and preferably a human. Specificexamples of “subjects” and “patients” include, but are not limited, toindividuals requiring medical assistance, and in particular, requiringtreatment for symptoms of heart failure.

As used herein, the term “pressure differential” means the difference inpressure between two points or selected spaces; for example between oneside of a flow control element and another side of the flow controlelement.

As used herein, the term “embolic particle” means any solid, semi-solid,or undissolved material, that can be carried by the blood and causedisruption to blood flow when impacted in small blood vessels, includingthrombi

As used herein, the terms “radially outward” and “radially away” meansany direction which is not parallel with the central axis. For example,considering a cylinder, a radial outward member could be a piece of wireor a loop of wire that is attached or otherwise operatively coupled tothe cylinder that is oriented at some angle greater than 0 relative tothe center longitudinal axis of the cylinder.

As used herein, the term “axial thickness” means the thickness along anaxis parallel to the center longitudinal axis of a shape or component.

As used herein, the term “axial direction” means direction parallel tothe center longitudinal axis of a shape or component.

As used herein, a “sealable connection” is an area where componentsand/or objects meet wherein the connection defines provides for aninsubstantial leakage of fluid or blood through the subject area.

As used herein, the term “lumen” means a canal, duct, generally tubularspace or cavity in the body of a subject, including veins, arteries,blood vessels, capillaries, intestines, and the like.

As used herein, the term “sealably secured” or “sealably connected”means stably interfaced in a manner that is substantially resistant tomovement and provides resistance to the flow of fluid through or aroundthe interface.

As used herein, the term “whole multiple” means the product contains nodecimal.

The present invention provides structures that enable several uniqueintracardiac and intraluminal valve devices and placement catheterstherefor. In some embodiments directed toward the intra-cardiac setting,these valve devices are intended to allow sufficient flow from the leftatrium to the right atrium to relieve elevated left atrial pressure andresulting patient symptoms but also prevent the amount of flow from theright atrium to the left atrium to minimize the potential for thrombi orother embolic material from entering the arterial circulation.

However, it should be appreciated that the invention is applicable foruse in other parts of the anatomy or for other indications. Forinstance, a device such as that described in this disclosure could beplaced between the coronary sinus and the left atrium for the sameindication. Also, a pressure vent such as is described in thisdisclosure could be placed between the azygous vein and the pulmonaryvein for the same indication.

Referring now to FIG. 1, one embodiment of invention is shown where theinvention is used as an interatrial pressure vent. FIG. 1 depicts theheart 1000 of a human subject. “LA” refers to the left atrium, and “RA”refers to the right atrium. The interatrial septum is depicted as 107.Interatrial pressure vent 100 includes a body element 101 and flowcontrol element 104, embodiments of which will be described in furtherdetail below. The body element 101 comprises flanges 102 and 103. Inthis and other embodiments described herein, flanges 102 and 103 may beannular flanges, which define a gap 2000 into which the septum 107 fits.In embodiments, after insertion, the interatrial pressure vent issecurely situated in an opening created in the interatrial septum. ArrowF in FIG. 1 shows the direction of flow. It can be thus seen that abuild up of pressure in the LA can be vented, by way of the inventivedevice, to the RA.

Referring now to FIG. 2, an embodiment of the interatrial pressure ventof the present invention is illustrated. Interatrial pressure vent 100includes body element 101 comprising a substantially open mesh andincluding a substantially cylindrical core segment (shown end on) 106and substantially annular flanges 102 and 103. Flanges 102 and 103 maybe comprised of any number of flange segments (or “flange elements” or“flange members”) 102 a-102 h and 103 a-103 h, that are attachedadjacent to the end of the core segment and extend radially outward fromlongitudinal axis of the core segment and flow control element 104.“Flange segments” may also be referred to as “legs” herein. The flanges102 and 103 (and thus the segments which comprise them 102 a-h and 103a-h) in this and all embodiments disclosed herein, may also be integralwith the core segment. That is, they need not be necessarily “attached”thereto but may be fabricated from the same material that defines thecore segment (including in the manners described above and herein) andthus may be contiguous therewith. The flow control element may beattached to the body element, for example at locations 105. The flangesegments in this and any embodiment of any annular flange may be formedof two individual strut elements or also can be formed of a singleelement. The flange segments may be generally rectangular in crosssection, circular in cross section, oval in cross section or some othergeometric shape.

In embodiments, the flange segments are designed to be more flexiblethan the core segment. In such embodiments, the increased flexibilitymay be achieved in several ways. In embodiments, a dimension of thesurface of the strut elements that make up the flange segments isaltered relative to the corresponding dimension of the struts (orelements, or members) that make up the core segments. FIG. 2A illustratesuch embodiments. FIG. 2A shows an example flange segment 103 a viewedend on. As shown, the end-facing dimension of strut element of 103 x hasa width D. By decreasing the width D in relation to the width of theoutward-facing dimension of the struts that comprise the core segment,an increased flexibility of the flanges in relation to the core segmentor other flange members (or portions thereof) can be achieved. FIG. 2Bshows an enlarged fragmentary cross-sectional of an embodiment of thedevice substantially shown in FIG. 6. The view is taken along line 7-7of FIG. 6. In this figure, the cross hatched area shows the area ofincreased flexibility. It can be seen that one area of the flangesegment is thus more flexible than another area. In embodiments wherethe strut elements are circular, then in a similar fashion, the diameterof the strut element could be made to have a diameters less than thediameter of the strut (or similar elements) comprising the mesh-likeconfiguration of the core segment. In embodiments where the flangeelement is made from a different section of material and is attached tothe core segment, the segment material could be chosen to have a greaterflexibility than the core segment (or remaining portion of the flangesegment or flange itself as the case may be). The choice of materialsbased on their flexibility will be apparent to those skilled in the art.In the ways described above, the flange segments can achieve greaterflexibility than the core segment (or the remaining portion of theflange segment or the flange itself as the case may be) thereby reducingprobability of damage to the tissue of the septum while allowing thecore segment to maintain a strong outward force against the septalopening and thus decrease the probability that the device could becomedislodged.

In embodiments having an open-mesh configuration for the body element101, the body element can be formed from a number of materials suitablefor use in a patient, such as titanium, nitinol, stainless steel,Elgiloy, mp34n, Vitalium, Mobilium, Ticonium, Platinore, Stellite,tantalum, platinum, or other resilient material. Alternatively, in suchembodiments, the body element 101 can be formed from a polymer such asPTFE, UHMPE, HDPE, polypropylene, polysulfone, or other biocompatibleplastic. The surface finish of the body element may be smooth with noedges or sharp discontinuities. In other embodiments, the surface finishis textured to induce tissue response and tissue ingrowth for improvedstabilization. In embodiments, the open mesh of body element 101 can befabricated from a resorbable polymer such as polylactic acid,polyglycolic acid, polycaprolactone, a combination of two or more ofthese or a variety of other resorbable polymers that are well known tothose skilled in the art.

In embodiments, the structure of the body element may be uniform andmonolithic.

In other embodiments, the body element (mesh or monolithic) comprisesporous materials to encourage tissue ingrowth or to act as a reservoirfor containing one or more compounds that will be released over timeafter implant to address numerous issues associated with the productperformance. These compounds can be used to diminish calcification,protein deposition, thrombus formation, or a combination of some or allof these conditions. The compound can also be used to stimulate anirritation response to induce tissue ingrowth. In embodiments, thecompound can be an anti-inflammatory agent to discourage tissueproliferation adjacent to the device. Numerous agents are available forall of such uses and are familiar to those who are skilled in the art.

In embodiments, the material that comprises the body may be multilayeredcomprising a coating of resorbable polymer or semipermeable polymer thatmay comprise various compounds that may be released, and in someembodiments in a controlled manner over time, after implant to addressnumerous issues associated with product performance.

The mesh can be formed from wire that is pre-bent into the desired shapeand then bonded together to connect the component elements either bywelding them or adhesively bonding them. They could be welded using aresistance welding technique or an arc welding technique, preferablywhile in an inert gas environment and with cooling control to controlthe grain structure in and around the weld site. These joints can beconditioned after the welding procedure to reduce grain size usingcoining or upset forging to optimize fatigue performance.

In other embodiments, the mesh can be formed from a hollow tube that hasbeen slotted using, for example, a machining laser or water drill orother method and then expanded to form the open structure. If asufficiently elastic and resilient material, such as nitinol, is used,the structure can be preformed into the finished shape and thenelastically deformed and stowed during delivery so the shape will beelastically recovered after deployment. The surface of the finishedassembly must be carefully prepared to insure is passivated and free ofsurface imperfections that could be nidus for thrombus formation.

In embodiments, the flow control element 104 is a tissue valve such as atricuspid valve, a bicuspid valve or a single flap valve formed frompericardial tissue from a bovine, porcine, ovine or other animal. Anynumber of cusps may be used. The flow control element is formed using anumber of processing steps and auxiliary materials such as are wellknown in the art.

The flow control element 104 can also be a ball valve, a duckbill valve,a leaflet valve, a flap valve, a disc in cage type valve, a ball in cagetype valve or other type of valve formed from a polymer or polymers or acombination of polymers, ceramics and metals such as dacron, teflon,polyurethane, PET or other suitable polymer; titanium, stainless steel,nitinol, MP35N, elgiloy, or other suitable metal; zirconia, siliconenitride, or other suitable ceramic. Valves or portions thereof maycomprise different stiffness/flexibly properties with respect to othervalves or portions thereof in the flow control element.

The flow control element 104 preferably extends to a point along theflange assembly 103 to enable creation of a sealable connection to theseptum wall after placement. This is more particularly shown in FIG. 3where it can be seen that in embodiments, the flow control elementextends beyond the length of the core segment and is folded and attachedto the core segment so as to create a lip that extends in a directioncenter of the opening in the vent. When the device is abutted againstthe septal wall, this lip forms said sealable connection and thus canreduce the likelihood that blood can flow through the septal opening viapathways between the outer surface (septal-facing surface) of theinteratrial pressure venting device and the septal opening. The flowcontrol element 104 is attached to the body element 101. This can beaccomplished by using a suture material, such as silk, nylon,polypropylene, polyester, polybutylester or other materials such as arewell known to those skilled in the art. In embodiments, flow controlelement 104 can be attached to body element 101 using adhesive bondingagents such as cyanoacrylate, polymethylmethacrylate, or other materialssuch as are well known to those skilled in the art. In otherembodiments, flow control element 104 can be attached to body element101 via staples, rivets, rings, clamps or other similar methods as arewell known to those skilled in the art.

As mentioned above, flow control element can be made of materialselected for its flexibility/stiffness. In embodiments where a loosevalve is desired that resonates more closely with the cycle of theheart, a however stiffness material may be chosen. In embodiments whereit is desired to open the valve when the pressure differential reaches aselected value, the material of the flow control element can be selectedand/or processed in a manner to open at the desired differential. Theleaflets or sections of the flow control element itself may alsocomprise areas of variable stiffness, and or may be more flexible orless flexible than other leaflets or components of the flow controlelement.

FIG. 3 shows the device implanted in the atrial septum of the heart of apatient. As can be seen from the figure, the core segment 106 can beformed contiguously with flanges 102 and 103 and thus flange segments102 a-102 h and 103 a-103 h respectively. In the embodiment shown, flowcontrol element 104 is contained within the core segment 106 so it doesnot extend beyond the face of the body element 101, thereby insulatingit from contact from other body structures or peripheral tissue, inembodiments, the core segment 106 can be extended to protrude beyond theinteratrial septum 107 and the flange assembly 102 and/or 103 on atleast one side of the interatrial septum 107 and can be formed with ashape that extends to create a lip in the manner described above. Inembodiments, the ends of the flange assemblies 102, 103 are formed tolie at a parallel angle to and against the septal wall along at least apart of its length to increase the area of contact and thereby decreasethe stress concentration against the septal wall.

Referring now to FIG. 4, an embodiment of the body element of thepresent invention is shown. This perspective view of the body element101 shows how, in embodiments, the ends of flange segments 102 a-102 h,103 a-103 h are rounded at their distal ends 115 and 116 to reducestress concentrations against the interatrial septum after placement.This rounded shape can easily be formed as part of the integral shape ofthe flange segment. In other embodiments, the thickness of the segmentin this area may be decreased to decrease the stress further against theinteratrial septum, which is similar to embodiments described above.Also similar to embodiments described above, if the segment is round,the diameter can be decreased in order to increase flexibility. Also, asdescribed above a different material of higher flexibility could be usedfor the end portions of the segments.

While rounded shapes at the ends of the flange segments reduce stress onthe septum, other variations on this theme are contemplated. FIGS. 7Athrough 7C illustrate embodiments where the shape of the end portions ofthe flange segments has configurations to achieveless stress against theseptal wall—among other goals. FIG. 7A is a side elevational view ofembodiment of the pressure venting device in its stowed configuration.Core segment 106 of body element 101 is shown and, in this embodiment,is integral with flanges 103 and 102. The individual flange segments arenot labeled; however, it is easily seen that flange 103 comprisessegments substantial similar to those described above. There is noeyelet or opening at the end of the segment in the embodiment shown.Flange 102 shows an embodiment where the flange segment is not comprisedof a triangular or multi-strut arrangement as described above but rathera single-member segment. Any flange of the present invention may beconstructed with single-member segment. An example single member isreferred to as 103 s. In this example, at the end of each single-memberflange segment (102 s) for example, there is an eyelet. FIG. 7B shows anembodiment similar to that shown in FIG. 7A where the end of thesegments 102 s are not eyelets but rather pads. FIG. 7C shows anotherembodiment where the ends of the segments 102 are paddle shaped. Othersmooth-edged shapes could be used, and it should be understood that suchshapes and configurations apply to all manner of flange segment ends,not only single-member segments. This would include the ends of flangesegments shown and described herein, for example with reference to FIGS.2 through 7.

FIGS. 7A-C also show embodiments having at least one flange segmentbeing longer than the other flange segments. Again, while represented assingle-member flange segments they need not be and as such aconfiguration with at least one longer segment may apply to anyflange-segment configuration disclosed herein. The benefits and purposeof having at least one longer flange segment will be described morefully below.

In embodiments, the outer ends of the flange segments 102 a-102 h, 103a-103 h are formed with integral marker holes or slots 109 and 110(shown in FIGS. 3 and 7 for example) in which markers 118 and 119 can bepositioned so the device may more easily be visualized usingradiographic imaging equipment such as with x-ray, magnetic resonance,ultrasound or other imaging techniques. Markers as disclosed herein maybe applied to the ends of any segments, not just those with holes oreyelets therein. A radiopaque marker 118 and 119 can be swaged, riveted,or otherwise placed and secured in the hole and thereby dimensioned tobe flush with the end of the segment. Markers may also be simplyattached or to end of a segment not having a hole. In all embodimentshaving markers, flange ends 115 and 116 are more visible when imaged. Inother embodiments, the markers 118 and 119 can be bonded with anadhesive agent such as cyanoacrylate or epoxy or a variety of othermaterials that are available and suitable for implant as are well known.The markers may be proud (as shown for example in FIG. 7) or flush withthe end of the flange segment. The radiopaque marker 118 and 119 may beformed of tantalum, tungsten, platinum irridium, gold, alloys of thesematerials or other materials that are known to those skilled in the art.Also markers 118 and 119 comprising cobalt, fluorine or numerous otherparamagnetic materials or other MR visible materials that are known tothose skilled in the arts can be incorporated together with theradiopaque materials, or in alternating locations of the flange segmentsto enable both x-ray and MR imaging of the interatrial pressure vent.Alternatively, the ends of the flange elements 102 a-102 h and 103 a-103h can be wrapped with a foil made of the same marker materials. Inembodiments, the radiopaque material can be laminated to the flangesegments and bonded through a welding process or using an adhesive suchas cyanoacrylate or numerous other adhesives known to those skilled inthe art.

Suture rings 117 can be formed in the body element to locate and fix theattachment site along the body element to the flow control element. Thesuture rings can be circular holes formed into the structure or theycould also be some other shape such as rectangular or triangular andalso can be formed as a secondary step, for example by standardmachining techniques, using a secondary laser machining step, or withelectro-chemical etching. Preferably the connection between a segmentand any other segment of the body element are formed with as large aradius as possible to increase resistance to fatigue failure. Also,preferably, all edges of the formed device are rounded to improvebiocompatibility and hemocompatibility.

The pattern of suture rings as well as which of the rings are selectedduring suturing may affect the properties of the flow control element.For example, in embodiments where it is desired to have the flow elementloose and flappable, less suture rings may be utilized and, in suchembodiments, RA-side end of the flow control element may containrelatively less sutures than the LA side. In other embodiments, it maybe desirable to keep the flow control element affixed to the coresegment for a increased length of the segment thereby reducing theamount of flow control element material that affecting flow. Still inother embodiments the top or bottom portion the flow element at the RAside may be sutured in such a way so as to allow the top or bottomportion of the flow control element to affect flow more than the otherportion respectively. Embodiments discussed below where the flow is“aimed” may utilize suturing patterns effective to enable the desiredflow control element configuration.

Returning to the flange segments, in an embodiment, the interatrialpressure vent 100 is comprised of an equal number of flange segments oneach side of the interatrial septum. In embodiments, there are eightflange segments on each side of the core segment. In another aspectthere are an equal number of suture rings and flange segments on oneside of the interatrial pressure vent. In other embodiments, there areseven flange segments on each side of the core segment. In otherembodiments, there are six flange segments on each side of the coresegment. In other embodiments, there are five flange segments on eachside of the core segment. In other embodiments there are four flangesegments on each side of the core segment. In other embodiments thereare three flanges on each side of the core segment. In other embodimentsthere are two flanges on each side of the core segment. In otherembodiments, there is one flange on each side of the core segment. Stillin other embodiments there are more flange segments as compared toflange segments. And in other embodiments, there are more flangesegments as compared to flange segments. As can be seen there are anumber of variations for the number of flange segments and the skilledartisan will appreciate that any number could be used while notdeviating from the scope and spirit of the invention.

Referring now to FIG. 5, the body element of an embodiment of thepresent invention is displayed in side view. The flange segments can beformed to produce a gap G (also referred to as an annular gap) betweenthe ends of flange segments on one side of the body and flange segmentson the other side of the body, when the device is in its “native” orun-deployed state. When the device is deployed, it flexes to accommodatethe tissue and as such the gap may expand when tissue is positionedtherein. In embodiments, this gap is slightly smaller than the thicknessof the interatrial septum. In other embodiments, the gap can be largerthan the thickness of the interatrial septum. In other embodiments thegap can be zero. In another aspect the gap can be negative: in this casethe flange segments on each side of the body can be formed to cross eachother in order to exert more pressure between the deployed flangesegments and the interatrial septum. Also shown in FIG. 5 are radiopaquemarkers 118 and 119, which in embodiments are shown to be locatedadjacent to the end of the flange segments.

Referring now to the embodiment shown in FIG. 6, the flange segments 102a-102 h are oriented so they are not directly opposed to flange segments103 a-103 h on the opposite side of the body element so that afterplacement there is no pinching points thereby reducing the chance fortissue injury. In embodiments, flange segments 102 a-102 h are arrangedmidway between adjacent ends of flange segments 103 a-103 h. Inembodiments the length of flange segments 102 a-102 h are similar to thelength of flange segments 103 a-103 h. However in other embodiments thelength of flange segments 102 a-102 h are identical to the length offlange segments 103 a-103 h; the length of flange segments 102 a-102 hare longer than 103 a-103 h; and the length of flange segments 102 a-102h are shorter than flange segments 103 a-103 h.

Referring now to FIG. 7, in embodiments having radiopaque markers it canbe seen that the radiopaque markers 118 and 119 may be placed into themarker holes 109 and 110 (or placed on the ends of flange segments thatdo not have holes) to locate the ends of the flange segments 102 a-102 hand 103 a-103 h with a non-invasive imaging technique such as with x-rayor MRI during or after the procedure. In embodiments, the markers 118and 119 can be formed to be flush in an axial direction with the outersurface and the inner surface of the flange segments 102 a-102 h and 103a-103 h. In another aspect, the markers 118 and 119 can be formed toextend in an axial direction beyond the outer surface of the flangesegments 102 a-102 h and 103 a-103 h, away from the interatrial septum.In embodiments, the markers 118 and 119 can be formed to extend in anaxial direction beyond the inside of the flange segments 102 a-102 h and103 a-103 h, toward the interatrial septum. In embodiments, the markers118 and 119 can be formed to extend in an axial direction beyond theinside and the outside of the flange segments 102 a-102 h and 103 a-103h. In embodiments, the markers 118 and 119 can be formed to be recessedin an axial direction within the surface of the inside of the flangesegments 102 a-102 h and 103 a-103 h. In embodiments, the markers 118and 119 can be formed to be recessed in an axial direction within theoutside of the flange segments 102 a-102 h and 103 a-103 h. Inembodiments, the markers 118 and 119 can be formed to be recessed in anaxial direction within both the inside and the outside of the flangesegments 102 a-102 h and 103 a-103 h. In embodiments, the markers 118and 119 can be formed to extend in a radial direction within the widthof the flange segments 102 a-102 h and 103 a-103 h. In embodiments, themarkers 118 and 119 can be formed to extend in a radial direction flushwith the width of the flange segments 102 a-102 h and 103 a-103 h.

Referring now to FIG. 8, an interatrial pressure vent 100 of the presentinvention is shown in its stowed configuration. In embodiments, theinteratrial pressure vent can be collapsed to a substantiallycylindrical shape for stowing in a delivery catheter during placement.Flange segments 102 a-102 h and 103 a-103 h can be fabricated to besubstantially equal in length. The “stowed position” is not meant toapply only to devices having flange segments of equal length but ratherto all embodiments of the venting device disclosed herein. Deviceshaving flange segments of varying length and orientation such as thosedescribed herein are also designed to stow in substantially the samemanner as shown in FIG. 8. In an embodiment 200 seen in FIG. 20, flangesegments 202 a-202 h and 203 a-203 h are formed on a slanted angle sothat, when marker elements are secured to the ends of the flangesegments, the flange segments can be stowed into a smaller volume. Inembodiments 300 seen in FIG. 21, flange segments 302 a-302 h are formedof alternating length to allow stowage into a smaller volume.

Referring now to FIG. 9, an embodiment of the distal end of theplacement catheter 111 of the present invention is shown in its openposition. The inner shaft 112 is fabricated with a center lumen 136 ofsufficient diameter to contain a guidewire 138 or also for use ininjecting contrast or other liquid. Commonly, the lumen would be sizedfor a guidewire of 0.010″, 0.011″, 0.014″, 0.018″, 0.021″, 0.028″,0.035″, 0.038″, 0.042″ or 0.045″. This lumen 136 can also be used tomeasure pressure at the distal end of the catheter using other equipmentand techniques that are well known to those skilled in the art. Thelumen 136 preferably extends through the entire length of the innershaft 112. Alternatively, the guidewire lumen 136 can extend for ashorter length in the proximal direction and then through a side hole(not shown) of the inner sheath. A corresponding side hole (not shown)is placed on the outer shaft 113 adjacent to the side hole in the innershaft 112 to create a pathway between the center lumen 136 of the innershaft 112 and the outside of the outer shaft 113. In this way it ispossible to pass a guidewire from this distal end of the inner lumen 136through the side hole and exchange the catheter over a guidewire than isless then twice the length of the catheter 111 while securing theguidewire position during exchange.

In embodiments, the inner shaft 112 is configured with a waist section120 to contain the folded interatrial pressure vent 100 between the gapformed in the space outside of this section of inner shaft 112 and theinside of the outer shaft 113. The inner shaft 112 is may be formed tocontain at least one circumferential groove 114 at the proximal end ofwaist section 120 that forms a recess between the inside of the outershaft 113 and the smallest diameter of the groove that is greater thanthe gap formed in the space between the waist section 120 and the insideof the outer shaft 113. Radiopaque markers 118 can extend in a radialdirection past the outer surface of the flange segments 102 a-102 h andin embodiments, when interatrial pressure vents of the present inventionare is folded into their stowed configuration and placed into positionover inner shaft 112, radiopaque markers 118 are dimensioned to fit intogroove 114. Other similarly dimensioned sections may be used; that is,that which fits into the groove need not necessarily be a radiopaquemarker. In embodiments, when interatrial pressure vents of the presentinvention are stowed in this manner, the gap between waist section 120and the inside of outer shaft 113 is not sufficient to allow radiopaquemarkers 118 beyond the distal end of groove 114 unless the outer sheath113 is retracted beyond the proximal end of groove 114.

The inner shaft 112 may be formed with a groove 121 on the distal end ofthe waist section 120 adjacent to the location of the distal end of theinteratrial pressure vents of the present invention are radiopaquemarkers 119 (or similar dimensioned members) can extend in a radialdirection past the outer surface of the flange segments 102 a-102 h andin embodiments, when interatrial pressure vents of the present inventionare folded into its stowed configuration and placed into position overinner shaft 112, radiopaque markers 119 are dimensioned to fit intogroove 121. In another aspect, the inner shaft 112 may be formed with acircumferential groove 114 on the proximal end of waist section 120 anda circumferential groove 121 on the distal end of the waist section 120The inner shaft can be formed of a variety of polymers or metals orcombinations of polymers and metals that are suitable for use in apatient. The inner shaft can be fabricated from a single length of PTFE,UHMWPE, FEP, HDPE, LDPE, polypropylene, acetal, Delrin, nylon, Pebax,other thermoplastic rubber, aliphatic or aromatic polyurethane, or avariety of other engineering resins that are well known to those skilledin the art. In embodiments, the inner shaft can be fabricated usingmultiple layers of two or three of the above-mentioned polymers tocombine desirable properties of each. For example, the outer surfacecould be composed of polyurethane to enable easier bonding of auxiliarycomponents to the inner shaft. The inner layer could be PTFE to conveybetter lubricity to the inner shaft. In embodiments, the inner shaft andor the outer shaft could be coated on the inner and or outer surfacewith a coating material that conveys specific properties to the shaftlike antithrombogenicity or lubricity. There are numerous availablecoating materials suitable for these purposes as are well known to thoseskilled in the art. The inner shaft can be compounded with aradiopacifier to increase the visibility of the inner shaft underfluoroscopy using bismuth salts such as bismuth subcarbonate, bismuthoxychloride, bismuth trioxide, tungsten powder, molybdenum powder orother radiopacifier such as are well known to those skilled in the arts.Similarly, the outer sheath can be fabricated from the same set ofmaterials as the inner sheath, in the same manner and using the samecoatings. Embodiments described below in connection with a flange ratherthan circumferential groove operate in substantially the same manner asdescribed above and herein, except the device does not necessarily haveprojections that fit into and are retained by the grooves.

Referring now to FIG. 10, a folded representative interatrial pressurevent 100 of the present invention is shown in its stowed position withthe placement catheter 111 of the present invention shown in its openposition. In practice, if the body of the interatrial pressure vent isfabricated of nitinol or other elastic material, when the placementcatheter is in its fully open position, the flange segments 102 a-102 hand 103 a-103 h would automatically recover into a shape like that shownin, for example, FIG. 4, hence this Figure is shown to illustrate theposition of the interatrial pressure vent 100 relative to the waistsection 120 and grooves 114 and 121. When radiopaque markers (orsimilarly dimensioned members) 118 extend beyond the thickness of theinside of body segment 101 of interatrial pressure vent 100, they form aprojection within interatrial pressure vent 100 that can be capturedwithin groove 114 to secure the position of the interatrial pressurevent 100 during placement. During deployment, the outer shaft 113 ofplacement catheter 111 is refracted a sufficient distance to reveal thedistal portion of the interatrial pressure vent 100 allowing the flangesegments 103 a-103 h to dilate radially away from the centrallongitudinal axis of body 101. By capturing the radiopaque 118 markerswithin the groove 114, the device can be repositioned easily withoutfurther deployment, or the device can be completely retracted andremoved from the patient without deployment as indicated in FIG. 17.

Referring now to FIG. 11, an interatrial pressure vent 100 of thepresent invention is shown completely stowed within the placementcatheter 111 of the present invention.

FIG. 11A shows an embodiment of the placement catheter similar inoperation to those described herein but operative to engage aninteratrial pressure vent by way of a slightly different mechanism thandescribed above in connection with circumferential grooves. This figureshows a schematic depiction of a stowed interatrial vent. Rather thanhaving the grooves as described above, this embodiment of a placementcatheter comprises an inner shaft having a flange or member 3000 (ratherthan a groove) which has a diameter larger than that of the inner shaftto grip and hold an end of the interatrial vent device as shown. Asshown in the figure, the flange and its segments (collectively referredto in the figure as 102) wrap around the ball-shaped flange 3000 andallow the interatrial pressure vent to be moved with the placementdevice in the manners described herein.

Referring now to FIG. 12, a placement catheter 111 of the currentinvention is shown. It should be noted that while the inner shaft isdepicted as having grooves in FIG. 12, the inner shaft may comprise theflange 3000 as described above in connection with FIG. 11A. The skilledartisan will appreciate that the operation of the device issubstantially similar whether grooves or flanges are utilized. Theplacement catheter 111 comprises a first handle component 128 that canbe attached to outer shaft 113. The first handle component can beattached to the outer shaft 113 using a variety of adhesive methods suchas solvent bonding using a solvent for both the handle and outer shaftmaterial; an organosol consisting of a solvent and polymer in solutionthat is compatible with both the outer shaft and the first handlecomponent; a polymerizable adhesive, such as polyurethane, cyanocrylate,epoxy or a variety of other adhesives as are well known to those skilledin the art. The first handle component can be fabricated from a varietyof metals such as aluminum, stainless steel, titanium or a number ofother metals and alloys as are well known to those skilled in the art.In embodiments, the first handle component 128 is fabricated from apolymer such as polycarbonate, or a variety of engineering resins, suchas Lexan, or others as are well known to those skilled in the art. Thefirst handle component comprises hand grip section 124 and tubular shaftsection 125. The tubular shaft section 125 can contain keyway 122 thatis formed or machined into the shaft section. The keyway is preferablyformed with three linear sections; a first linear section 131, a secondlinear section 132 and a third linear section 133. Each of thesesections is formed to traverse along a path primarily parallel with thecenter axis along the length of the first handle component but each isdisplaced radially from one another by at least about half of the widthof the keyway. The placement catheter 111 also can comprise a secondhandle component 129 that can be attached to inner sheath 112. Thesecond handle component can be fabricated from the same variety ofmetals and polymers as the first handle component. The two handles canbe fabricated from the same materials or from different materials. Thesecond handle component can be attached to the inner sheath in the samemanner and using the same materials as the first handle componentattaches to the outer sheath. In embodiments, the second handlecomponent can contain threaded hole 126 for containing set screw 127.The set screw can be twisted to capture the inner shaft against thesecond handle component. The second handle component 129 also cancomprise a second hand grip section 134 and second tubular shaft section130. The second tubular shaft section can contain key 123 that is formedor machined of suitable dimension to adapt to keyway 122 of first handlecomponent 128. When assembled, second handle component 129 can beslideably moved relative to first handle component 128 in a mannercontrolled by the shape and length of the key way 122. As the secondhandle 129 is advanced relative to the first handle 128, it can beappreciated that the inner sheath 112 will slide in a distal directionout from the outer sheath 113. It can be appreciated that when thesecond handle component 129 is assembled, the key 123 is slid into thefirst linear section 131 and advanced until it hits the edge of thekeyway formed between the first linear section 131 and the second linearsection 132. In order for the second handle component 129 to advancefurther, it must be rotated and, once rotated, it can be advancedfurther but will stop when the key 123 hits the edge of the keywayformed between the second linear section 132 and the third linearsection 133. The keyway dimensions are preferably selected withconsideration for the combination of lengths of other components in theplacement device. A first position, defined as the position when the key123 is in contact with the proximal edge formed between the first linearsection 131 and the second linear section 132, is preferably determinedso, when fully assembled and with the interatrial vent in its stowedposition within the placement catheter, the outer shaft 113 willcompletely cover the length of the interatrial pressure vent 100 as isdesired during catheter placement. The keyway dimensions can also beselected to result in a second position, defined as the position whenthe key 123 is in contact with the distal edge formed between the secondlinear section 132 and third linear section 133. The second positionwould preferably be selected to reveal the full length of flangesegments 103 a-103 h but retain flange segments 102 a-102 h within theouter shaft 113 of the catheter. The length of the third linear section133 would preferably be selected so that, when the second handlecomponent 129 was advanced completely against the first handle component128, the full length of the interatrial vent 100 would be uncovered bythe outer shaft 113 and the device would be deployed. A variety of otherconfigurations of the first and second handle components could be usedfor this same purpose. The first handle component tubular shaft section125 and the second handle component tubular shaft section 130 could bethreaded (not shown) so the first handle component 128 could be screwedinto the second handle component 129. Alternatively, gear teeth (notshown) could be formed in the first tubular shaft section 125 of thefirst handle component 128 and a gear wheel (not shown) could beincorporated into the second shaft tubular section 130 of the secondhandle component 129. The gear wheel would preferably be chosen to meshwith the gear teeth and the second handle component 129 could beadvanced toward the first handle component 128 by rotating the gearwheel. A variety of other design configurations could be utilized tocontrol the relative location between the first handle component and thesecond handle component as are well known to those skilled in the art.

FIGS. 13 through 17 show embodiments of a system for treating heartfailure of the present invention. More specifically FIGS. 12 through 19show how the placement catheter is introduced and positioned in apatient and methods for placing the interatrial valve in a patient. Theinteratrial pressure vent 100 is presterilized and packaged separatelyfrom the placement catheter 111. Sterilization can be performed byexposing the device to a sterilizing gas, such as ethylene oxide, byexposing the device to elevated temperature for an adequate period oftime, by using ionizing radiation, such as gamma rays or electron beamor by immersing the device in a fluid that chemically crosslinks organicmolecules, such as formaldehyde or gluteraldehyde and then rinsed insterile water or sterile saline. For each of these sterilizationmethods, consideration must be given to compatibility of the materialsso device performance is not adversely affected as a result of thesterilization process. Also, the packaging design and materials must becarefully considered with the sterilization procedure, poststerilization handling and storage, environmental exposure duringstorage and shipment, and ease of handling, opening, presentation anduse during the procedure.

In embodiments, interatrial pressure vent 100 can be assembled usingcomponents that have been pre-sterilized using one of the above methodsor others that are well known and the final assembly may be accomplishedin an aseptic manner to avoid contamination.

In embodiments, the interatrial pressure vent 100 can be suppliednon-sterile and be sterilized around the time of use using one of theabove methods or by other methods well known by those skilled in theart.

Similarly, the placement catheter 111 may be pre-sterilized and packagedseparately from the interatrial pressure vent 100. Sterilization can beperformed using a similar method to the interatrial pressure vent 100 orusing a different method from the same choices or using some othermethod as is well known by those skilled in the art.

In embodiments, an interatrial pressure vent 100 and the placementcatheter 111 can be supplied pre-sterile and in the same package. Inanother aspect, the interatrial pressure vent 100 and the placementcatheter 111 can be preloaded and supplied pre-sterile.

Prior to insertion, the interatrial pressure vent 100 is preferablyfolded and stowed onto the placement catheter 111. This can beaccomplished in a sterile field and using aseptic techniques in thefollowing steps. First the interatrial pressure vent 100 is presented tothe sterile field and the placement catheter 111 is presented to thesterile field. Second, the interatrial pressure vent 100 and placementcatheter 111 are inspected for visible signs of damage, deterioration orcontamination. Third, the second handle component 129 of the placementcatheter 111 is retracted fully so the outer shaft 113 exposes the innershaft 112 to the maximum extent allowed. Fourth, the interatrialpressure vent 100 is positioned in the correct orientation over theinner shaft 113 of the placement catheter 111 with the inner shaft 113oriented through the center of the flow control element 104. Fifth, theflange segments 102 a-h and 103 a-h are folded away from each other andthe flange segments 102 a-h and 103 a-h and the core segment 106 arecompressed radially to fold the interatrial pressure vent 100 into asize and shape that will fit over and onto the waist section 120 of theinner shaft 112 with the distal ends 115 of flange segments 102 a-haligning with the proximal groove 114 of inner shaft 112. In embodimentscomprising a flange as described in FIG. 11A the flange segments 102 a-hand 103 a-h are folded away from each other and the flange segments 102a-h and 103 a-h and the core segment 106 are compressed radially to foldthe interatrial pressure vent 100 into a size and shape that will fitover the flange 3000 described on FIG. 11A. This folding may beaccomplished with the aid of an insertion tool (not shown) that retainsthe interatrial pressure vent 100 in a stowed position on inner shaft112 and then advancing outer shaft 113 over the stowed interatrialpressure vent 100 and displacing the insertion tool, thereby leaving theouter shaft 113 completely covering the interatrial pressure vent 100and mating with the distal tapered tip 140 of the inner shaft 112. Inother embodiments, this can be accomplished by hand using the fingers ofone hand to hold the distal ends 115 of the flange segments 102 a-102 hin position at groove 114 of the inner shaft 112 and advancing the outershaft 113 over the inner shaft 112 enough to hold the flange segments102 a-102 h in place. Completion of the loading procedure isaccomplished by progressively advancing the outer shaft 113 until itcompletely covers the interatrial pressure vent 100 as shown in FIGS. 11and 11A. While the below discussion regarding placement of theinteratrial pressure vent uses the placement device shown in FIGS. 9-11as an example, the description on placement and the procedure thereforeis also meant to apply to embodiments where the inner shaft comprises aflange rather than grooves.

Positioning of the loaded interatrial valve 100 and placement catheter111 in preparation for implanting the interatrial valve 100 in thepatient can be accomplished by: first gaining vascular access; second,positioning a guidewire 121 in the right atrium of the patient; third,positioning an introducer (not shown) into the patients right atrium;fourth, locating the interatrial septum; fifth, advancing the introducerthrough the interatrial septum and into the patient's left atrium;sixth, advancing the guidewire 138 into the left atrium; seventh,retracting the introducer; eighth, advancing the loaded placementcatheter 111 and interatrial pressure vent 100 into position so thedistal end and approximately half of the stowed length of theinteratrial pressure vent 100 is protruding through the interatrialseptum and into the patient's left atrium as shown in FIG. 13.

In embodiments, positioning of the loaded interatrial valve 100 andplacement catheter 111 in preparation for implanting the interatrialvalve 100 in the patient can be accomplished by: first gaining vascularaccess; second, positioning a guidewire 138 in the right atrium of thepatient; third, advancing the loaded interatrial valve 100 and placementcatheter 111 over guidewire 138 by inserting the guidewire into andthrough lumen 136 and advancing placement catheter 111 into thepatient's right atrium; fourth, locating the interatrial septum; fifth,advancing the placement catheter 111 through the interatrial septum andinto the patient's left atrium so the distal end and approximately halfof the stowed length of the interatrial pressure vent 100 is protrudingthrough the interatrial septum and into the patient's left atrium asshown in FIG. 13.

Implanting interatrial pressure vent 100 into a patient can beaccomplished, once the loaded interatrial pressure vent 100 andplacement catheter 111 are in position as shown in FIG. 14, by first,retracting first handle component 128 toward second handle component 129while holding second handle component 129 until flange segments 103 a-hare fully uncovered as shown in FIG. 15, and as can be verified byvisualizing the markers 119 using fluoroscopy or using echocardiography;second, retracting the placement catheter 111 with partially deployedinteratrial pressure vent 100 toward the patient's right atrium untilthe flange segments 103 a-h are in contact with the left atrial side ofthe interatrial septum, as shown in FIG. 16, and as can be verifiedusing the same techniques mentioned or as can be perceived by the userbased on the resistance felt against further proximal movement of theplacement catheter 111; third, continuing to retract the outer sheath113 by retracting first handle 128 toward second handle 129 until theouter sheath 113 is retracted beyond the proximal end of groove 114 ofinner shaft 112 and also uncovers flange segments 102 a-h, at which timethe flange segments 102 a-h of interatrial pressure vent 100 will deployreturning to the preloaded geometry and capture the interatrial septumbetween the flange segments 103 a-h and flange segments 102 a-h as shownin shown in FIG. 18; fourth, the inner sheath is retracted through theflow control element 104 of interatrial pressure vent 100, into thepatient's right atrium as shown in FIG. 19; fifth, the first handlecomponent 128 is advanced away from the second handle component 129 toreposition inner shaft 112 into the position relative to outer shaft 113it was in during placement and the placement catheter is removed fromthe patient and the procedure is completed.

In other embodiments, implanting interatrial pressure vent 100 into apatient can be accomplished, once the loaded interatrial pressure vent100 and placement catheter 111 are in position as shown in FIG. 14, byfirst, advancing second handle component 129 toward first handlecomponent 128 while holding first handle component 128 until flangesegments 103 a-h are fully uncovered as shown in FIG. 15, and as can beverified by visualizing the markers 119 using fluoroscopy or usingechocardiography; second, retracting the placement catheter 111 withpartially deployed interatrial pressure vent 100 toward the patient'sright atrium until the flange segments 103 a-h are in contact with theleft atrial side of the interatrial septum, as shown in FIG. 16, and ascan be verified using the same techniques mentioned or as can beperceived by the user based on the resistance felt against furtherproximal movement of the placement catheter 111; third, continuing toretract the outer sheath 113 by advancing second handle 129 toward firsthandle 128 until the outer sheath 113 is retracted beyond the proximalend of groove 114 of inner shaft 112 and also uncovers flange segments102 a-h, at which time the flange segments 102 a-h of interatrialpressure vent 100 will deploy returning to the preloaded geometry andcapture the interatrial septum between the flange segments 103 a-h andflange segments 102 a-h as shown in shown in FIG. 18; fourth, the innersheath is retracted through the flow control element 104 of interatrialpressure vent 100, into the patients right atrium as shown in FIG. 19;fifth, the second handle component 129 is retracted away from the firsthandle component 128 to reposition inner shaft 112 into the positionrelative to outer shaft 113 it was in during placement and the placementcatheter is removed from the patient and the procedure is completed.

For a variety of reasons, it may be necessary or desirable to removeinteratrial pressure vent 100 and placement catheter 111 during any partof the procedure without further risk or injury to the patient. This ispossible as follows: if, for any reason, it is desired for the device tobe removed before outer shaft 113 is retracted and flange segments 103a-h are deployed, then the placement catheter 111 with interatrial valve100 can simply be retracted out through the same pathway as introduced.

If, following deployment of flange segments 103 a-h it is necessary ordesirable to remove the device, then the interatrial valve 100 can beretracted into the placement catheter 111 by advancing first handle 128away from second handle 129, while holding second handle 129 stationary,thereby advancing outer sheath 113 distally through the interatrialseptum and over the flange segments 103 a-h. In embodiments, radiopaquemarkers 118 placed in marker holes 109 are captured in groove 114 (seeFIG. 17) and cannot fit in the gap between waist 120 of inner shaft 112and inner surface of outer shaft 113, so as outer sheath 113 isadvanced, flange segments 103 a-h are forced to fold inward toward theirstowed position and are retracted back onto inner shaft 112 and withinouter sheath 113. Once outer shaft 113 is fully advanced, catheter 111can be retracted as shown in FIG. 17 to be removed out through theinteratrial septum and out through the same pathway as introduced.

FIG. 19A is embodiment of the invention designed to enhance theretrievability of the device. The procedure for implanting the device issubstantially similar to that which is described above; however, thereare variations to the placement catheter and the device, which will bedescribed below. As discussed in connection with FIGS. 7A through 7C,embodiments of the interatrial venting device comprise at least oneflange segment being longer than the other flange segments. Theembodiment schematically shown in FIG. 19A preferably works with suchembodiments having at least one flange segment that are longer inrelation to the other flange segments; thus the segments shown in the RAhave the same reference number as the longer segments in FIGS. 7Athrough 7C, i.e., 102L. In embodiments utilizing the techniques shown inFIG. 19A, the opening 113 a of outer sheath 113 of placement catheter isangled or has a more surface area on one side relative to the other. Theplacement catheter is oriented during the procedure such that the angledopening (or the plane of the opening itself) is at an angle more normalto the septal wall 107. In the embodiment shown in FIG. 19A, that angleappears to be around 45 degrees with respect to the septal wall 107, butany angle which provides an more normal angle with respect to the septalwall may be used, and any opening which provides more surface area ofthe outer sheath 113 on one side with respect to the other side may beused. Reference numerals 4000 through 4050 refer to steps in the processdescribed below. The process is largely similar to that described aboveor with respect to any well-known placement catheter system and process,therefore only the applicable differences will be described. As can beseen at steps 4000 through 4020, the placement catheter is positionedand the device is in the beginning stages of deployment. At steps 4030and 4040, the as the outer sheath 113 is retracted and on the RA side(or when the inner shaft is advanced while the outer sheath is on the RAside, which is not shown), the opening allows one of the longer flangesegments 102L to be deployed after other flange segments have beendeployed and are thus in contact with the septum 107. The at least onelonger flange segment 102L is retained in the placement catheter systemby way of the outer sheath 113, the length of which extends further onone side than the other due to the opening and thus covers the longersegment 102L while the other shorter segments have been deployed. Inthis way, the operator of the placement catheter can determine if theinteratrial device is in the proper position. If not, the operator canstill retrieve the device up until the last point prior to fulldeployment, i.e., when at least one of the longer flange segments (102Lfor example) is still retained in the placement catheter by the outersheath 113. If it is in proper position, the deployment may commence.

Another deployment embodiment is now described in connection with FIG.19B. This deployment embodiment may be used with any embodiment of theinteratrial vent described herein. Reference numerals 5000 through 5050refer to steps in the process described below. At step 5000, the LA sideof the device (generally referred to in this figure as 100) is deployedon the LA side of the heart. Further deployment is shown at step 5010and the outer sheath is retracted into the RA side of the heart, whichallows flow control element 104 to exit the placement catheter.Placement catheter is equipped with a balloon, which is in fluidcommunication, for example, with lumen 136 described above or guide wire138. The skilled artisan will appreciate other configurations in which aballoon catheter may be provided in the placement catheter system. Upondeployment of the LA side flange or shortly thereafter, balloon 139 isinflated (shown in step 5020). The inflation of the balloon optionallycoupled with a pulling-back motion of the placement catheter 111 holdsthe device 100 against the LA side of the septal wall 107 and therebyprevents the device 100 from dislodging during deployment and/or movingin a direction away from the septal wall. Step 5040 shows the fulldeployment of the device 100 while the balloon 139 is inflated. Whensatisfactory deployment is achieved, the balloon 139 is deflated and theplacement catheter system is removed (shown at step 5050).

Now referring to FIG. 20, an interatrial pressure vent 200 of thepresent invention is shown. In embodiments, flange segments 202 a-h and203 a-h can be formed with graduating length to reduce interferencebetween flange segments 202 a-h and 203 a-h during handling, folding andloading. In embodiments, radiopaque markers 218 and 219 protrude intothe inner cylindrical shape of the stowed position of the interatrialpressure vent and each flange segment 202 a-h and 203 a-h differ inlength by at least the width of the radiopaque markers 218 and 219. Inembodiments, each flange segment 202 a-h and 203 a-h differ in length byat least at least 1 mm. In embodiments, each flange segment 202 a-h and203 a-h differ in length by at least 2% of the overall length ofinteratrial pressure vent 200 in the position shown in FIG. 20.

Now referring to FIG. 21, an interatrial pressure vent 300 of thepresent invention is shown. In embodiments, flange segments 302 a-h and303 a-h can be formed with alternating length to reduce interferencebetween flange segments 202 a-h and 203 a-h during handling, folding andloading. In embodiments radiopaque markers 318 and 319 protrude into theinner cylindrical shape of the stowed position of the interatrialpressure vent 300 and alternating flange segments 302 a, c, e, and g arelonger than flange segments 302 b, d, f and h, and correspondingly,flange segments 303 b, d, f and h are longer than flange segments 303 a,c, e and g by at least the width of the radiopaque marker. Inembodiments, alternating flange segments 302 a, c, e and g are longerthan flange segments 302 b, d, f and h and, correspondingly, flangesegments 303 b, d, f and h are longer than flange segments 303 a, c, eand g by at least 1 mm. In one aspect the alternating flange segments302 a, c, e and g are longer than flange segments 302 b, d, f and h and,correspondingly, flange segments 303 b, d, f and g are longer thanflange segments 303 a, c, e and g by at least 2% of the overall lengthof interatrial pressure vent 300 in the position shown in FIG. 21.

Referring now to FIG. 22 and FIG. 23, the body element 401 of aninteratrial pressure vent with integral thrombus filter and retrievalcone 442 of the present invention is shown. In embodiments, conicalstruts 444 are affixed to body element 401 at attachment points 446 andconverge at apex 450. In embodiments, conical struts 444 comprise singlebeams of similar material to flange segments 402 and 403 and can beattached to the body element or formed at the same time as the bodyelement using techniques described in this specification, and are thusintegral with the remainder of the device. In embodiments the spacebetween adjacent struts 444 is about 2 mm. In embodiments, the spacebetween adjacent struts 444 is about 4 mm. As can be appreciated,conical struts 444 will protrude into the right atrium of the patientafter implant and spaces between conical struts will function to blockthe passage of solid material larger than the space between adjacentstruts 444. This will provide the function of preventing emboli that arelarger than the space between the adjacent struts 444 from passing fromthe right atrium to the left atrium.

Referring again to FIG. 22 and FIG. 23, in embodiments the shape of theconical struts 444 is not straight. In embodiments the shape of theconical struts 444 can be concave when viewed on end as depicted in FIG.22. In embodiments the conical struts can be curved in a direction awayfrom the chord formed between the apex 450 and the attachment points446. In embodiments there can be a hole 451 through apex 450 largeenough to receive a retrieval snare (not shown). It can be appreciatedthat conical struts 444 and apex 450 can be used to aid retrieval of theinteratrial pressure vent from a patient at some time after the implantprocedure using a method as follows: A catheter tube with an internallumen at least as large as apex 450 can be placed into the patientsright atrium using standard techniques and imaging equipment. Aretrieval snare can be fabricated from the proximal end of a guidewirebent sharply by about 180 degrees and this snare can be inserted throughthe catheter tube and advanced into the patient's right atrium and withthe assistance of fluoroscopy advanced through hole 451 or aroundconical struts 444. Once the retrieval snare is engaged in this manner,it will be possible to retract the interatrial pressure vent byadvancing a catheter tube while holding slight tension on the snare andthereby guide the catheter tube over apex 450 and onto conical struts444. As the catheter tube continues to advance, with some tension on thesnare it will be possible to force the conical struts inward, therebyforcing the flange segments 402 to begin folding inwards. When theconical struts are nearly completely in the catheter tube, the cathetertube can be held in a stationary position and the snare wire retractedagainst it, thereby causing the attachment points 446 between theconical struts 444 and the flange segment 402 to be retracted into thecatheter. Flange segments 402 can begin to be retracted into thecatheter at this point and the distal ends of flange segments 402 can bediverted toward the patients left atrium but will also fold inward andinto the catheter. Once the flange segments 402 are inside of thecatheter tube, the snare can be held stationary and the catheter tubecan be advanced further, through the interatrial septum and over flangesegments 403. Once the flange segments 403 are retracted into thecatheter, the catheter and snare can be moved together to retract theinteratrial pressure vent into the patient's right atrium and outthrough the pathway through which it was introduced.

Referring now to FIGS. 24 and 25 an alternate embodiment of interatrialpressure vent 500 is shown. In embodiments, flow control element 504 iscomprised of leaflets 541 a-c. Body element 501 is comprised of coresegment 506 and flange segments 502 a-l and 503 a-l (not fully visiblein FIG. 25); the number of flange segments being a multiple of thenumber of leaflets. This configuration improves the symmetry of strainagainst the flow control leaflets and also improves the uniformity ofmotion by the flow control element to changes in blood flow.

In embodiments the number of leaflets comprising the flow controlelement is three and the number of flange segments on each side of thecore segment is twelve. In embodiments, the number of leafletscomprising the flow control element is three and the number of flangesegments on each side of the core segment is nine. In embodiments, thenumber of leaflets comprising the flow control element is three and thenumber of flange segments on each side is six.

In embodiments, the number of leaflets comprising the flow controlelement is three and the number of flange segments on each side isthree. In embodiments, the number of leaflets comprising the flowcontrol element is three, the number of flange segments on one side ofthe core segment is twelve and the number of flange segments on theother side of the core segment is nine. In embodiments, the number ofleaflets comprising the flow control element is three, the number offlange segments on one side of the core segment is twelve and the numberof flange segments on the other side of the core segment is six.

In embodiments, the number of leaflets comprising the flow controlelement is three, the number of flange segments on one side of the coresegment is twelve and the number of flange segments on the other side ofthe core segment is three. In embodiments, the number of leafletscomprising the flow control element is three, the number of flangesegments on one side of the core segment is nine and the number offlange segments on the other side of the core segment is six. Inembodiments, the number of leaflets comprising the flow control elementis three, the number of flange segments on one side of the core segmentis nine and the number of flange segments on the other side of the coresegment is three.

In embodiments, the number of leaflets comprising the flow controlelement is three, the number of flange segments on one side of the coresegment is six and the number of flange segments on the other side ofthe core segment is three. In embodiments, the number of leafletscomprising the flow control element is two and the number of flangesegments on each side of the core segment is twelve. In embodiments, thenumber of leaflets comprising the flow control element is two and thenumber of flange segments on each side of the core segment is ten. Inembodiments, the number of leaflets comprising the flow control elementis two and the number of flange segments on each side of the coresegment is eight.

In embodiments, the number of leaflets comprising the flow controlelement is two and the number of flange segments on each side of thecore segment is six. In embodiments, the number of leaflets comprisingthe flow control element is two and the number of flange segments oneach side of the core segment is four. In embodiments, the number ofleaflets comprising the flow control element is two and the number offlange segments on each side of the core segment is two.

In embodiments, the number of leaflets comprising the flow controlelement is two, the number of flange segments on one side of the coresegment is twelve and the number of flange segments on the other side ofthe core segment is ten. In embodiments, the number of leafletscomprising the flow control element is two, the number of flangesegments on one side of the core segment is twelve and the number offlange segments on the other side of the core segment is eight. Inembodiments, the number of leaflets comprising the flow control elementis two, the number of flange segments on one side of the core segment istwelve and the number of flange segments on the other side of the coresegment is six.

In embodiments, the number of leaflets comprising the flow controlelement is two, the number of flange segments on one side of the coresegment is twelve and the number of flange segments on the other side ofthe core segment is four. In embodiments, the number of leafletscomprising the flow control element is two, the number of flangesegments on one side of the core segment is twelve and the number offlange segments on the other side of the core segment is two. Inembodiments, the number of leaflets comprising the flow control elementis two, the number of flange segments on one side of the core segment isten and the number of flange segments on the other side of the coresegment is eight.

In embodiments, the number of leaflets comprising the flow controlelement is two, the number of flange segments on one side of the coresegment is ten and the number of flange segments on the other side ofthe core segment is six. In embodiments, the number of leafletscomprising the flow control element is two, the number of flangesegments on one side of the core segment is ten and the number of flangesegments on the other side of the core segment is four. In embodiments,the number of leaflets comprising the flow control element is two, thenumber of flange segments on one side of the core segment is ten and thenumber of flange segments on the other side of the core segment is two.

In embodiments, the number of leaflets comprising the flow controlelement is two, the number of flange segments on one side of the coresegment is ten and the number of flange segments on the other side ofthe core segment is two. In embodiments, the number of leafletscomprising the flow control element is two, the number of flangesegments on one side of the core segment is eight and the number offlange segments on the other side of the core segment is six. Inembodiments, the number of leaflets comprising the flow control elementis two, the number of flange segments on one side of the core segment iseight and the number of flange segments on the other side of the coresegment is four.

In embodiments, the number of leaflets comprising the flow controlelement is two, the number of flange segments on one side of the coresegment is eight and the number of flange segments on the other side ofthe core segment is two. In embodiments, the number of leafletscomprising the flow control element is two, the number of flangesegments on one side of the core segment is six and the number of flangesegments on the other side of the core segment is four. In embodiments,the number of leaflets comprising the flow control element is two, thenumber of flange segments on one side of the core segment is six and thenumber of flange segments on the other side of the core segment is two.

In embodiments, the number of leaflets comprising the flow controlelement is two, the number of flange segments on one side of the coresegment is four and the number of flange segments on the other side ofthe core segment is two.

FIG. 26 shows and alternate embodiment wherein the core segment 106 isovular rather than circular and thus the core segment is a cylindroid orelliptic cylinder rather than a simple cylinder. This embodiment is moreconducive to a bicuspid (or “duckbill”, bivalve, or two-leaflet)configuration for the flow control element. The duckbill configurationis generally referred to as flow control element 104 in this figure. Theinventors have found that the bi-valve configuration is able to openmore fully when coupled with a core segment in the shape of acylindroid.

FIGS. 27 and 27A show another embodiment of an interatrial device havingintermediate flange segments for a more secured fit against the septalwall. In embodiments, the intermediate flange segments are part ofanother a third annular flange situated on the same side of the septalwall as one of the other flanges. Reference numerals 6000 through 6040refer to steps in the deployment of such an embodiment and will bediscussed in connection with the structural features of the embodimentto illustrate this embodiment's utility and operation. The deploymentprocess is similar to those described above, and to any commonly-knowncatheter based delivery process and as such the details of the processwill not be discussed herein. Steps 6000 to 6020 show the deploymentprocess steps proceeding in much the same manner as described herein. Atstep 6030, intermediate flange segments 602 and 604 of intermediate (orthird) annular flange are deployed on the RA side. In this embodiment,intermediate flange segments 602 and 604 are shorter than the majorityof the flange segments of the RA-side flange. As such, segments 602 and604 are deployed prior to other longer segments and contact the septalwall 107 at points closer to the septal opening than the contact pointsof the longer segments. In this manner, the intermediate segments 602and 604 (and the flange which they comprise) provide increased stabilityof the device. Any number of intermediate segments may be used althoughit is preferable to have at least two. As with other embodiments, thestiffness of the intermediate segments may be altered so as to differfrom other flange segments of the device to avoid damage to the septalwall, i.e., lesser stiffness/greater flexibility, or to provideincreased stability, i.e., greater stiffness/lesser flexibility. Thechoice of stiffness/flexibility variations must be balanced against thedesired goals.

FIG. 27A is a side elevational view of embodiment discussed inconnection with FIG. 27. In FIG. 27A the pressure venting device in itsstowed configuration. Flanges 102 and 103 are shown with the flangesegments that comprise them (flange segments not individually labeled).Core segment is again shown as 106. At a point between the end of thecore segment 106 and proximal end of the RA side flange segment 102, theintermediate segments (collectively referred to as 600) emerge.Intermediate segments may be integral with the venting device orattached thereto in the manners described above.

In other embodiments, the flow control element is configured to directthe blood flow in a desired direction. FIGS. 28A through 28C show suchembodiments. In FIG. 28A interatrial device 100 is shown implanted inthe atrial septum 107 of the heart in the same manner as shown inFIG. 1. Flow control element 104 is configured to aim the, shown in thisfigure as in the direction toward the superior vena cava. FIGS. 28B and28C show a more detailed view of embodiments that enable the flow to bedirected in a desired direction. As shown in FIG. 28B, flow controlelement comprises a baffle-like flange 104 a that extends at a downwardangle and in the corresponding direction. In use, such embodimentdirects the flow downward. FIG. 28C shows an embodiment where the flowis directed upward. The valve material (e.g. material for leaflets) ofthe present invention can be sized and secured to the 100 in manner todirect the flow. For example, the flow control element may contain acurved tubular member whose opening points toward the direction of flow,or the flow control element may otherwise comprise an opening directedat the area of interest. In embodiments with baffles, the stiffness ofthe baffle 104 a may be varied, for example, made stiffer. The length ofthe baffle can also be varied depending on the desired flow direction.The baffle can be a separate member attached to the flow control elementor it may be made of the material and/or integral with the remainder ofthe flow control element.

FIGS. 29A through C show exit profile shapes of the flow control element104. In these figures, the flow control element 104 is being viewed fromthe RA side and thus the direction of flow is understood to coming outof the page at an angle substantially normal to the page. If the flowcontrol element is a valve as described herein, folding and suturingpatterns may be employed to achieved these exit profile shapes. In otherembodiments, the end of the flow control element may be provided with aplate, or a partially frustoconical end piece, having an openingdefining the two-dimensional shape shown in the Figure. The skilledartisan will appreciate that other exit profile shapes may be fashioned.The selection of an exit profile shape may provide advantages such asdirecting flow, preventing thrombi from moving across the septal divide,and/or reducing injury to surrounding tissue.

Another embodiment of the invention is shown in FIG. 30. In thisembodiment, the core segment 106 and flanges 102 and 103 of the deviceare substantially similar those described herein. Instead of the flowcontrol elements described above (or in addition thereto) a tube-likemember 700 is secured to the core segment 106. The tube member 700 isattached to the core segment 700 in a manner to allow the RA end of tubeto extend into the RA in an axial direction, thus the tube's length mustbe sufficient to extend a distance into the RA. It has been found thatthe tube 700 configured in this manner prevents embolic particles fromentering the tube and crossing over the septal divide into the LA. Thedistance that the tube 700 extends into the RA and beyond the plane ofthe RA-side flange opening (indicated by dotted line) should be at leasta 1 mm but may be up to 2 cm in preferable embodiments. Even atrelatively short lengths (such as where the tube extends only a fewmillimeters into the RA), the inventors have noted the surprisinglyunexpected result of a reduction of embolic particles passing through.This is due to, in part, the tendency of embolic particles to collectalong the surface of the septal wall and move toward the septal opening(or opening of an implanted device) with each cycle of the heart. Byextending away from the septal wall 107, the tube provides an effectivebarrier to the embolic particles that would otherwise travel toward andpossibly through the septal opening.

Although the present invention has been described and illustrated in theforegoing exemplary embodiments, it is understood that the presentdisclosure has been made only by way of example, and that numerouschanges in the details of implementation of the invention may be madewithout departing from the spirit and scope of the invention, which islimited only by the claims which follow.

What is claimed is:
 1. A device for treating a heart condition in apatient, said device for implantation into the atrial septum of saidpatient's heart, said device comprising: a core segment defining apassage to enable fluid to flow from one side of said atrial septum toanother side of said atrial septum when implanted; a first annularflange disposed distal to the core segment and adapted to engage a firstsurface of said atrial septum; a second annular flange disposed proximalto the core segment and adapted to engage a second surface of saidatrial septum, the second surface of said atrial septum opposite to thefirst surface of said atrial septum; and a flow control elementcomprising a baffle disposed proximal to the core segment and configuredto direct in a selected direction blood flowing through the passage froma left atrial side of the atrial septum to a right atrial side of theatrial septum, the baffle positioned at a fixed angle relative to thecore segment and configured to extend into the right atrial side of theatrial septum.
 2. The device of claim 1 wherein at least one of thefirst annular flange and the second annular flange is more flexible thanthe core segment.
 3. The device of claim 1 wherein at least one of thefirst annular flange and the second annular flange comprises a pluralityof flange segments.
 4. The device of claim 3 wherein at least one of theplurality of flange segments is longer than another one of the flangesegments.
 5. The device of claim 3 wherein at least one of saidplurality of flange segments comprises a radiopaque marker.
 6. Thedevice of claim 1 wherein the device is self-expandable upon deployment.7. The device of claim 1 wherein the device is balloon-expandable. 8.The device of claim 1 wherein the flanges define a gap to accommodatethe septal wall.
 9. The device of claim 8 wherein the gap is variable,thereby enabling the accommodation of variable septal thicknesses.